If anyone is reading this and sees compatibility as their primary reason for staying with a Chromium browser: I have been using Firefox as my main browser for many years now, and I can count on one hand the number of times where I've been hit by compatibility issues.

The big one is anything to do with video calling — things often work but not as well, or you can voice call but not use video, or something like that. Most of the time the call works well enough, or I use a native app anyway, in which case this isn't a problem, but I suspect this is the thing people are most likely to run into in practice.

The other one is WebUSB, which is useful for certain tools that flash hardware (e.g. keyboards) from the browser. This is rarer, but I still have Chrome around so I can still use these tools. And mostly there's another option anyway, it's just that WebUSB makes things more convenient.

I have heard people complain about Cloudflare, but I've never noticed this. I suspect this is less to do with Chrome/Firefox, and more to do with privacy settings that Firefox makes more accessible. But again, I've never had an issue with Cloudflare myself, so I can't say much about this.

Other than that, I genuinely can't think of the last time I wanted to use a website but couldn't because of Firefox. And even in the above situations, it's rare that I actually run into issues, it's just something I'm aware of as a possible cause if something happens. Most of the time things work perfectly well.

Slack is what makes me use Brave every day because its stupid huddles feature doesn’t support Firefox. But other than that, yeah. Firefox is fine.

Same but for Safari. I use it as my daily driver and rarely get issues related to unsupported APIs. Everything seems to work fine, the only issues I ever hit are related to the Apple VPN.