Joining a Meet meeting is easy, just like joining a Teams meeting is easy. Both are much, much easier than Webex & Zoom, which irritate with attempts at forcing client software installation.
When Firefox transitioned their plugin format they dropped support for over a year (after receiving more than a year of deprecation warning). At the time it require a separate installed plugin (which defeats most of the purpose of integrating with the browser). Safari support has also been spotty.
I really hate Google's account system. I don't even use Google, but find myself juggling 4 or 5 accounts for work, school, family. If I go to `classroom.google.com` I get a "Verify it's you <account I don't intend to use>". I'm expected to click "Next" and click a few more times before I can select the right account.
I don't have direct experience with Teams (I assume it's similar to Google). Being all-in is clearly the easiest solution--using it every day, having it as your only video solution, having an account and staying signed in. The annoyance is the friction that it can't be your only solution and when it's one of many there's a lot of mental energy to jump through the hoops.
Zoom does have a web version and the native app is almost inappropriately too easy to install. Joining a video chat just means having a meeting ID or clicking a URL.
This isn't unique to Google; it applies to any kind of single sign on with lots of different products. You're always better off maintaining separate browser profiles so you can seamlessly switch between them than forcing everything into a single profile and endlessly logging out and logging in on all these different sites. I used to do this with Facebook too back when I was using a different account for work development.
And there's also the "poor man's" version of this which even many non-technical users know about, which is to use Chrome for one account and Firefox for another.