Funny

I would say probably not, because that's really hard to do and probably not worth it. Rendering hair physics is indeed very computationally intensive, but that's not what the AI is really doing, it's generating frames out of noise and statistical likelihood of pixel values based on training data and previous frames. It's not really generating hair or cats per se, just what's likely to be next based on what was before and what was in thousands and thousands of other videos of cats. It kinda bypasses the the need for physics simulation. However, this process too is extremely computationally intensive and expensive for that matter, but typically they're short low resolution videos generated by online services that are running datacentres to be able to do this and doing so at a massive financial loss while they figure out where the money is going to come from with this emerging tech. It's both more impressive and easier than hair simulation in some ways and also harder and worse in many ways.

Ok so to backtrack a bit on my former "definitely", I should acknowledge that I have no means of externally verifying my claim, though I still stand by it. I'll list some of what leads my to believe this along with counterarguments. The list is technical and contextual.

Contextually:

• Other videos on the channel have comments asserting they're AI generated, people throw this around a lot and are often wrong so doesn't mean much, but it's a clue.
• Cats are not usually known to be fans of jumping on trampolines. (definitely not impossible they might decide to go on a trampoline, but it feels kinda anthropomorphic that they'll frequently go and attempt to induce bouncing deliberately)
• Other videos on the channel are kind of ambiguously part of one household or several I think they're trying to create the impression of one, but hedging their bets by being vague about it. Details like the house surrounds and buildings visible from the backyard are both fairly consistent but also still change which is sorta weird. I'm pretty sure I've seen them change within one video.
• They're all relatively unlikely things happening with cats, which are a popular choice for easy internet attention.
• All their videos have this same low quality, highly compressed 720p resolution, crappy kind of look that should be a lot less common nowadays but fit with the viral home video vibe. It's associated with the actual videos AI generates, and also with helpfully hiding the biggest flaws of AI videos so you could be seeing both what they've generated and also some deliberate attempts to compress aggressively to hide flaws.

Technically:

• The single most compelling detail is that between 14 and 15 seconds the cat's tail wipes across much of the screen and the previously straight cement path becomes a curved path with totally different lighting.
• At the beginning of the video the cat has a bell collar that jingles just from the cat walking, by 11s it's obscured by fur, but it's then never seen again and also does not jingle ever again despite the cat literally jumping up and down.
• In another of their videos, at the 24s mark, they have made little cars for their cats out of laundry baskets with wheels that the cats ride down their stairs. Setting aside the implausibility of this whole scenario, one of the cats literally drives and steers to turn and face the direction of the stairs before descending. The laundry basket car apparently somehow has it's own locomotion and capacity to steer with the cat doing so adeptly.
• There's a table at the beginning of the video that appears have two legs supporting the front of it, but no legs to hold up the back of it. It's also placed in a weird spot right in front of a doorway. These people might just make weird choices around furniture placement and it could be that this is a type of sidetable that's designed to be partially attached to or supported by a wall. But I thought it was strange.
• Very unnatural noisy sound but relatively clear human voices. Could just be the mic picking up a lot of noise, but the quality of that noise signal is a bit weird.
• The entire video has this wavy, morphy, effect. To me I sometimes see it as an almost oil painting look that's very characteristic of AI generated video. It's this uncanny look of far too realistic to be drawn and animated by people but too painterly to be photographic. A lot of that subjective feel can be chalked up to high compression, but it's absolutely the first thing that jumped out to me before any of the other details
• The ladder going up the trampoline casts a shadow from the leg on the right, but not the left and also that shadow begins split as if composed of two poles even though it seems it should be just one, and then later that shadow becomes just one. (This data point is pretty weak I must admit, analysing shadows can get pretty dicey, reality often looks different to expectation, after all people have tried to use unexpected shadow placement to disprove the moon landings and were very wrong)
• The trampoline has a little white patch with a diagram of some kind. This is probably the closest thing to text in the video (the actual title GFX reading "whatever you say human" etc., were probably put on there by a real human later) and as is often the case with text in AI gen video, it gets garbled and wonky at times. Basically, every time there's a fair bit of motion this diagram gets pretty broken up and strange. However, that diagram does remain pretty much consistently the same diagram without degrading in to something else over the course of the whole video and the fact that it only gets messed up during motion is also what you'd see with motion blur and very compressed poor quality video.
• Over the course of the video when the cat is jumping, especially on the way back down as it lands, it's facial features morph and change and disappear and pop back in to existence. The eye on the camera left in particular seems to variably disappear, or get squashed, or kind of close like a wink in a way I'd not expect of a cat. Maybe this is just compression struggling with motion blur, and too few index frames but I don't think so.
• At 49s in, as the cat lands a jump it's eyes not only morph and change shape very weirdly, but also, they remain sharp while the rest of the whole cat is blurry from motion. Also in the time between landing it's previous jump and the transition at 51s the cat is sitting and turns its head to its left. If you look frame by frame here, the cat's face goes completely haywire and also it's tail kinda fades in and out of existence or at least moves unnaturally.
• The transition at 51s is circumstantially suspicious too. The videos on this channel generally seem to try and imply it's the same bunch of people making them and the same cats and try to imply a kind of candid, as-it-happened approach yet here in this video there's an attempt to hide a cross dissolve transition behind a focus shift. That's more of a deliberate editorial technique which is a weird departure from the other videos, I suspect it might be because the generated video had some unacceptable problems but they still wanted to hit that 1 minute mark so they tried to cut around them. The focus shift itself looks more like what you'd expect from a blur effect in classic editing software than a true optical focus change. Also half way through this transition is what appears to be something like a kind of buffering symbol. It's a circle of 8 individual segments. I think actually such an artifact can appear optically from real photographic equipment with extreme bokeh, but I think it's very unlikely we'd see it from the phone footage this purports itself to have been captured on, given the lack of bladed apertures on phone lenses. Also during this transition, the footage we're transitioning to starts on the cat jumping up and while it's obviously blurry during this blur transition, I can still kinda see that it looks like the cat's entire head disappears for a frame there and that might have been something the people behind the channel were hoping to hide behind the transition and why unlike their other videos they felt the need to put an edit in there at all. Admittedly if that were the case, they could have just chosen not to include that jump at all and cut a bit later in to the generated clip, so it's not a smoking gun but also those AI video generators don't produce very long clips so you don't have a lot to work with.

Dang, are you sure? I’ve seen cats do stuff like this with their owners and trusted people, so am kinda baffled why someone would need to use AI for this.

Without any way to actually verify my claims, I can't be absolutely sure, but it's this balance of context and accumulation of weirdnesses that makes me very confident that yes, it's AI generated along with most or more probably all the other videos on their channel. Cats sometimes do funny and unexpected things and sometimes people are filming at just the right moment to capture it, but it's precisely because those things are unusual and rarely captured that they're big hits online. Cat videos are a popular genre, which makes collecting and publishing them attractive to people. However, this channel to me, is suss even without too much visual analysis because the moments they've supposedly captured and put up there seem to be about cats behaving in implausible ways that line up with anthropomorphic themes. They want attention and views and so it's not enough that the cats merely be doing funny stuff, it can't be just a cat that got on a trampoline all by itself and walked around, it had to jump repeatedly and induce bouncing on purpose like humans would do on a trampoline. And it couldn't just be the one rare cat that does it, in another video, several different cats do. Their other videos seem to revolve around cats going on rides in elaborate contraptions set up for them. The cats are pretty passive in those videos so they're arguably not acting like people per se, but unlike cats they never get out of the contraptions they're in, or run off once the 'ride' is over, they're remarkably chill. Maybe one person's weird cat acts that way, but these people have at least 4 cats and they seem to do this kind of thing all the time in multiple scenarios. I had an ad blocker so I don't know if they've tried to run ads on their channel but if they do, that probably tells you everything you need to know about the why aspect of it. Even if not, it could just be someone messing around, having fun with new tech or just interested in seeing how much attention they can garner by any means necessary.

EDIT: They sell merchandise with their channel name. That's the why part answered.