If Netscape had a large paid install base and still failed because a free browser became ubiquitous, what makes you think doing that now when the free browsers are already ubiquitous would work? Especially when it also has to compete with what is essentially already what you’re describing, Librewolf (or just Firefox + Arkenfox).
I’ve never used EndeavourOS or Manjaro, but if you’re looking for something similar to Bazzite (gaming-ready, not immutable) and Arch-based I’d check out CachyOS. I’ve been using it for a good while now and I really like it.