Fedora has "Cool Other Package Repositories" or COPR. They're a place for community members to build and publish arbitrary RPM packages. Some are well curated and high quality, others less so.
Thanks for mentioning this! I heard of COPR a while back but never really explored it until this morning after I saw your mention. It definitely could be considered an alternative to AUR/PKGBUILD for Fedora (and it has >24,000 packages already hosted on https://copr.fedorainfracloud.org/).
Do I understand it correctly that it also builds the user provided packages? I guess that's similar to [0] but having something (semi?) official is pretty nice.
vast majority of stuff in the aur has no arm version, how about COPR?
The AUR and PKGBUILDs are pretty much just an Arch thing.
But on a distro like Fedora, where the default repo is fairly complete and well-groomed (with the odd package hosted in a 3rd party repo), having something like the AUR is a moot point IMO.