I'd say there's a very good chance you'll catch the quality just by watching 2 minutes of their videos. Most AI content has this annoying AI voice... Or it's close to brainrot... Or it seems like a science video but then half of it doesn't sound right. And at some point it'll inevitably turn to some slop stock footage.
Then there's some stuff in the middle which is harder to judge.
And then there's the videos I'm immediately sure someone spent 2 weeks writing them, figuring out things... I mean there's no way 3blue1brown, nilered, veritasium, electroboom, numberphile, stevemould etc use current-day AI and arrive at videos of the quality they regularly put up. A lot of it is original content, some never done before. And AI can't really do that, it's mostly good at combining existing stuff...
I'd say gut-feeling will do in 90% of cases. AI assisted storywriting or video production isn't all that great, yet... I mean I can't tell if someone uses AI color grafing or upscaling... But in terms of the content, there is just no way any 3blue1brown video is made with a substancial amount of gen AI.