Since I just had to deal with a Teams issue, I'm going to list some reasons I dislike it. Obviously, everyone's mileage is different and something that bothers me may not bother others. However when people complain about Teams, it's generally because of the following:

It's slow. I don't care what MS says, Teams is really slow. It is slow to start, it's slow to load content, and it's slow to upload content to, and it's slow to navigate around in. This doesn't mean it's painfully slow, but it's slow enough that I think about it and that means it's too slow. There is no excuse for performance like this in 2025 unless the excuse is you're packing as much telemetry and data collection garbage as possible into the application.
The integrations are really clunky (and also perform poorly). For example, if I upload a 30 second mp4 file it will go into Sharepoint and be served in MS Teams through MS Stream. Think about that for a second. A video file needed to be uploaded to Teams, shipped to Sharepoint for network storage, then read by MS Streams to feed back to Teams. Just render the fucking file in Teams. This isn't hard. With the way they have it setup, the performance is terrible, the user experience is terrible, and it's insulting that we're being fed this bloated garbage. For context, I'm on a fiber connection and I still see buffering issues and slow video load times only in Teams so it clearly isn't just something on my end.
It randomly loses the ability to connect. Everything else works including other MS products but Teams won't connect. Within the last 2 years, there have been at least half a dozen times where I turned on my computer in the morning and everything works except Teams. After a lot of searching for a solution, the fix was to delete two registry keys. Seriously, I have to go into the registry occasionally to delete two keys that are in no way tied to Teams based on their location in the registry before Teams will connect again when this happens. What the fuck is happening that Teams relies on two obscure registry keys that aren't even located under any MS Teams nodes. Fucking awful.
Did I mention performance? It is worth mentioning again because of how terrible it is. It is usable and gets the job done but people have no idea how much faster this could be if the bloat was removed. Slack isn't exactly great from a performance perspective either but (at least in my experience) it's much better than Teams.
I keep getting prompts about copilot in Teams which is infuriating considering I've declined every time and it's still enabled and still prompts me. I don't need AI to summarize a one-sentence chat message FFS and I certainly don't need help writing that sentence. Stop interrupting my flow to popup messages about features I've already told you I don't want to use.

The majority of the above comes down to bad design leading to bad UX and performance. Why are they using a Streams instead of rendering the video in-app natively? Because it was cheaper to just tie into their Streams service. Why is it that only Teams randomly loses the ability to function? Because for some reason it relies on a legacy registry connection key because...reasons?

There isn't a single bad thing about MS Teams, it's a bunch of kinda bad things that together make the product terrible. We should demand better of our software products but all leverage has been given to the people who already control these things so we're just screwed from getting actual good software made.

[–] AnAverageSnoot@lemmy.ca 11 points 1 day ago (1 children)

Also, screen sharing seems to take up most of your available RAM for some reason. When screen sharing, your chat window pops up to show everyone all your chats. The annoying ass top bar that needs to be moved every time and can't remember its last location. Is teams a group chat, channel a group chat, or is group chat a group chat? Most add-ons are useless. Why does setting up a web hook notification with Teams require Power Automate? And why does it need a fixed schema? Just let me send any message I want!!

[–] hornywarthogfart@sh.itjust.works 5 points 1 day ago

Yeah the entire piece of software is just really poorly optimized, they use ambiguous language and labels, their controls are constantly in the way (when sharing), and so forth. It is objectionably a bad experience because so many fundamental things about it could be improved drastically.

Instead they needed a modern messaging application and Skype was poisoned by their handling of it so they took a bunch of individual things they had lying around and jammed them all together into a product they called Teams. If you actually look at how it works that is what they did. It's why MS Streams is used for video, Sharepoint is used for network stores, AD is used auth, and so forth. It isn't a single product but rather a shell of discrete things that were made to work together but clearly not originally designed in that way given the performance.

[–] chellomere@lemmy.world 4 points 22 hours ago (1 children)

What about it using at least 1 GB of RAM, and growing continuously while you're using it until the OOM killer has gotten enough and kills it?

[–] hornywarthogfart@sh.itjust.works 1 points 20 hours ago

Yep 100%

[–] KindaABigDyl@programming.dev 5 points 1 day ago* (last edited 1 day ago) (1 children)

Ah I see. So the complaints aren't really in the feature-set or design of the app, but rather the optimization.

That makes sense to me now. I was coming from the perspective of "I really like how information is organized and how collaboration works" not from a "does this app function well."

I've never really had any performance issues, personally. Perhaps that's bc I always used the Linux app back when I used teams and had a beefy PC. It had its own issues, but they were really with getting it to run in the first place. Once I could get it running, it always worked well for me.

Also, I was using it a couple years ago, pre-copilot, so maybe that's added to the crappiness

[–] hornywarthogfart@sh.itjust.works 1 points 20 hours ago* (last edited 20 hours ago)

I never used it on Linux so I can't speak to that but it's pretty bad on Windows. It wasn't great a couple years ago (on Windows) and it's only gotten worse. The downward slope of the product quality seems to be steeper each year as well. It's really frustrating to witness since they could have put out something great.

They were already sunsetting Skype, MSN Messenger was basically gone (or was it previously rolled into Skype? I can't remember). They could have started from scratch and built a really great communication tool using all of the knowledge they gained running the aforementioned products and not carrying forward all of the tech debt and glue they had to add to make the older services work with modern architecture. But they didn't and now the majority of the corporate world suffers relentless little pain points while using the software.

Not to mention it's poor quality has splash damage: loss of productivity due to issues and performance, increased IT tickets, increased computer specs to run the new features MS thinks we all need despite people not asking for. All of that amounts to millions (billions?) of dollars more spent each year for products that are themselves subpar. That cost is only growing as well.