My main problem is that I prefer other frontends to Firefox. I mostly use Vivaldi and think it's great, but of course it's Chromium based. I read somewhere that it's just way easier to base a browser on Chrome than it is to base one on Firefox. It would be great if the frontend and backend were separated with a unified API and you could simply choose a frontend/interface (Vivaldi) with whatever backend/engine (Gecko). That's not how it (currently) works though.

There are Firefox forks, but they're just that: forks with slight modifications. Vivaldi and Arc are basically completely different browsers. Even Orion isn't based on Gecko, it's based on WebKit.

Add to that small compatibility issues with certain websites/web apps that aren't Firefox' fault, but rather developers targeting Chrome instead of "100 % web standards". Still, as a user you'll likely into (small) issues from time to time.

People saying "just use Firefox" have a very narrow view on how any of this works and I sometimes feel like it's some form of elitism where the cool kids use Firefox and everybody using anything else are "lesser people". In reality, people have different requirements and priorities. It's similar to people posting "just use Linux" under every article talking about problems with Windows.

Yes, Chrome and Google sucks, I agree, but there isn't a single universal solution to this problem.