Many vendors look at the userAgent. I’d be surprised if Microsoft Teams org doesn't have some soft incentives pushing Edge and if not edge Chromium-based browsers.

Then again, there are definitely some Firefox behaviors that differ from the WebKit-derived engines (webkit, blink, etc); for a few years Notion editor had very different UX in Firefox for this reason. They eventually fixed it though! Firefox's profiler is also excellent, I always analyze my Chrome profiles in https://profiler.firefox.com/ when I'm optimizing CPU use.