This isn't new territory for Google. They did the same thing to Windows Phone, simply excluding any of their products from working on Windows Phone, even when other developers tried to step in and fill the gap. [2]
[1] https://www.zdnet.com/article/former-mozilla-exec-google-has...
[2] https://www.google.com/amp/s/techcrunch.com/2013/01/02/micro...
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.
And there are no widespread reports of it not working on Firefox, so it's something specific to your machine. Not a general case.
Isn’t this the problem? Why do I have to disable something in Firefox to make it work for a google product.
It's not a Firefox problem, it's extensions you chose to install that neither Firefox nor Google have anything to do with.
But try disabling browser extensions and see if that fixes it -- a majority of the time that's the culprit. With videoconferencing specifically, it's often an extension or setting to block videos from autoplaying.