Here is one long standing issue with many related compat links attached: https://bugzilla.mozilla.org/show_bug.cgi?id=975444

and two other webcompat examples: https://webcompat.com/issues/56933 https://webcompat.com/issues/68844

Just to give an idea. That said, Meet works fine for me, besides some features, like background, which they have only implemented for Chromium based browsers (maybe Safari!?) - that is a bit annoying, as I doubt that it would break the devs leg to implement something for Firefox as well.