The reality is that with so many different users, there will be lots of opinions about the best way to do things, and especially in OSS communities, it's literally impossible to keep everyone happy.
Mozilla should let others do UX experimentation (like Zen, which is an Arc copy), and focus on the core performance and compatibility of the engine itself. Keep FF itself more streamlined as a core browser, and empower others to build fancy stuff on top.
And ditch literally anything related to ads & sponsorships, which have no place in a piece of tech so foundational to the open web.
- I wanted ad-blocking on Android, so I tried out Firefox on mobile.
- Then there were times I wanted to sync browser history/tabs between mobile and desktop, so I picked up Firefox on desktop again.
- I fell in love with reader mode (and using the narrate feature to listen to articles when my eyes get tired)
- I flirted with Zen browser, but now that Firefox has vertical tabs and tab grouping, I'm having trouble finding a reason to use Zen
Firefox basically does everything I want it to do, and it's incredibly rare that I need to open a chromium-based browser to handle something Firefox can't do.
No one really cares about a majority of the UX sugar, IMO.
I personally find the LLM context menu useful and reading mode awesome, but these are not features that by themselves would drive me to use the browser.