Comment by homebrewer

You can have the best browser in the world, and it's not gonna help you if nobody tests for it because its market share is approximately 0%. We're already seeing people getting stuck in endless captchas because they're using a weird browser that behaves differently to 95% of other users, and shitty websites inadvertently relying on bugs in Chromium which results in stuff not working, or running slow as molasses, in FF.

I've been running into both pretty much daily. As a long time Firefox users (since 2.0 almost exclusively), it didn't used to be like that, it's a recent phenomenon.

Much can also be said about them removing features and not implementing things people keep asking for for decades; for example, the vertical tab feature request was there for more then 20 years, I think?

It's not a criticism of developers, they're doing what they can, it's obvious set by managers.