God forbid they tested across the multiple common browsers out there other than Chrome. Every other software development company creating a web app does that, why doesn't one of the biggest?
Sadly no, ever web app company definitely doesn't test under Firefox. I'm at the point where I use Firefox for general web browsing and Chromium for most web apps.
In the last 5 years I've run across maybe 1 site that didn't work properly in Firefox. And another that MIGHT not have worked right, but I was only guessing it was related to FF.
However, since FF dropped PWA support I do use Chrome for a handful of sites that either are PWAs or you can use Chrome's open as application feature, which is real nice for a few things. Is that what you mean by "Web Apps"?
Thanks. I remember trying it about a year ago but it didn't work well for some reason. Will give it another try now that I hear it's working well for you.
No, the PWA thing is a separate annoyance. What I find is that in a lot of web apps, the app mostly works fine but has bugs that break certain things or are seriously inconvenient in Firefox only. Two I've experienced recently are Nextcloud Office slideshows (I need to search for/open a bug report honestly) and a web based billing software we use at work.