I fortunately am not a front end programmer, so I'm only a hardware customer. As a result I buy the best hardware and software.
I do feel for your plight. At one point I was making an App for my side hobby and was dreading the moment I needed to compile for iOS. (I had recently used a butterfly keyboard.)
I have encountered this mentality often. I'm not sure if Apple users have so many bugs that they are used to it, or if it's part of the fanaticism.
I had so many bugs on iphone 6 I was baffled because the marketing "It just works". Upon voicing my issues, I was told from numerous people, "it's probably just doing X,Y,Z". Like that's an acceptable reason for bugs.
Firefox is doing the damage to themselves.