Speaking as a developer myself, it's likely not the devs' fault that Teams is as shit as it is. They are all intimately familiar with its shortcomings and are perfectly able and willing to fix them, but are prevented from doing so by management who insist that shovelling crapware down their customers' throats is far more important.
Honestly, what I find frustrating with Teams is that both MSN Messenger and Skype were right there. It's not even an issue of copyright or trademark as MS owns both. Even just lazily re-branding Skype would have been head-and-shoulders above what we have now.
Teams is the evolution of the excellent Microsoft Lync which then became the horrible Skype for Business which then was replaced by the superior Microsoft teams.
It's that. It's been a hot minute, but (IIRC) for me it was the less-than-great UI/UX that really adds up to a high friction experience. Especially when compared with software like Slack or Discord.
Having talked to people who were in charge of making some strategic decisions regarding a business messaging application...
Slack/Discord is "too complex and confusing". Apparently the pile of unsorted chats, group chats, and meeting chats, are superior to Discord's threading model.
Also corpos literally do not notice that teams is slow as molasses which is a big part of the friction. You could show them a perfect demonstration that Teams' UI is so much slower to react to anything (nevermind load the actual resource) than the competition and that they often have a 1000+ms audio RTT in meetings (not a hyperbole) and the business people would be like "yeah, I guess? Who cares?"
Corporate types literally can't understand that bad audio and audio latency costs a huge percentage of revenue in lost productivity because everyone's constantly talking over each other and simultaneously being too afraid to speak because the audio delay makes it impossible to fit into a lull in the conversation and also everyone is in a competition for the tiniest shittiest mic with the worst noise canceling that somehow stacks on top of Teams' pretty bad noise cancelation such that their voice is being noise canceled and you're just left with like 1.2 kHz of actual range and somehow everyone seems fine to spend their entire day listening to that and aaaaaaaaa I have a headache and I want to die
Then after work you get on a discord call with the mates and everyone is crystal clear with no noticeable latency, even the students on a secondhand 30 € gaming headset.
Then again, in a world that needs developers badly everywhere, a developer that stays in a job where management forces them to maintain crappy software, is an idiot (or plain greedy).
/also a developer
Not in Europe - for now. Will be different of course if fascist America murders us all over here. Or Putler. Doesn't make much of a difference in the end...