The beloved lightweight distro
If ever Firefox actually starts to disgust me and not just disappoint me, I'll stop maintaining it and look at forks.
But it won't be Librewolf, because the default settings are just a cargo-cult of self-contradictory "privacy enhancements" without any sane threat model that make the browsing experience much worse for little gain.
Because it's a two-part ting. Being popular enough and finding a maintainer (from them limited pool of official maintainers there are) who does it.
The AUR is unofficial and no one cares much if updates are delayed there but the offcial repositiories have higher standards and -and that's related to the list of browsers also not in the official repos- maintaining google-based browsers is a pain in the ass (in fact I'm used to seeing warnings because librewolf is once again flagged aus out-of-date but the AUR maintainer didn't have the time to fix the latest build yet).
Because no Package Maintainer wants to maintain it, is my guess.
I thought it is already maintained? And it's popular enough to have someone who would do it?
AUR package maintainers are not the same as Arch repo package maintainers. Anyone can be an AUR package maintainer.
And it is not straightforward to become arch maintainer. There has to be a level of trust in that person. The team shouldn’t be too big to manage. And there are other considerations too.