The AUR is a different kettle of fish entirely, though. I do see your point, but the AUR is solving a problem common to all distros; hosting a repository for applications that there isn’t willingness or capacity to host in the official binary repos.
Installation, removal, dependency management, etc are all still handled by pacman. As others have pointed out there are great tools available to aid in AUR usability. My favorite is aurutils.
Thanks for the detailed answer. I think I have a clearer picture of the problems it’s trying to solve and the solutions it’s delivering.
It also now seems connected to immutable distros I’ve heard about recently. So I guess the idea there is that the OS is just a tiny core set of libraries that never have to change, then the applications have their dependencies bundled, instead of requiring them as system dependencies.
I’m not convinced it’s something I want as a user, but more importantly not something I need.
From a development perspective, it seems downright seductive, allowing almost total freedom of opinion.