Despite my above rant, I still use Firefox as my primary browser. The web works absolutely fine on it. I think I’ve encountered one site that required chrome to work correctly in the last year and that’s a huge improvement over where we were back in the early 2000’s with IE.
No, there’s other reasons why people don’t switch, compatibility is not the issue.
I have to switch to chromium often, unfortunately. Various websites are untested with Firefox, and many apps such as Teams are not compatible with FF. Probably better than the early 2000’s but still really bad.
I use teams on Firefox and haven’t encountered any issues. Admittedly I only use it occasionally, as I do mainly use the desktop app.
I think they added some compatibility in the past year or so but I had issues detecting my microphone on Linux just 2 weeks ago. I’ve had some smaller ecommerce sites fail to load properly on Firefox/Librewolf, Red Hat’s Training website doesn’t work on Firefox, and also some features on apps like Google Meet and Miro are unavailable. It’s nothing that makes firefox unusable, and I can always open up ungoogled chromium when needed, but it is a serious issue for browser diversity and competition that the web has defaulted to chrome now.