Firefox was originally created with XUL and was still using XUL until around 2019 when it was totally removed. And nobody really loved and preferred Mozilla the browser at the time Phoenix/Firefox came out, this is why it immediately got huge adoption, despite being unofficial for a good while.
The crap began with Mozilla leadership some years after Firefox - perhaps at the time of their mobile OS and smartphone efforts, but in general when starting to care more for getting the sweet Google cash and doing BS token attempts at anything they would "brainstorm" than being an actual player in the browser space.
I can assure you that PLENTY of people loved Mozilla and were pissed off by Firefox.
I'm still astonished that it gained fans, anyhow their crappy behavior towards users, privacy etc clearly began at that point, from what I recall. That then it got worse and worse with the years, absolutely
The crap began with Mozilla leadership some years after Firefox - perhaps at the time of their mobile OS and smartphone efforts, but in general when starting to care more for getting the sweet Google cash and doing BS token attempts at anything they would "brainstorm" than being an actual player in the browser space.