Arch is not the only distribution that has a service for providing "use at your own risk", unreviewed, user-submitted content; Fedora has Copr, the openSUSE project has the Open Build Service (OBS), and Ubuntu has Personal Package Archives (PPAs). Each of those services allow a person to sign up without any review process and build packages for download by other users of the distributions.

However, there are important differences between those services and the AUR. They provide a build environment that is similar to the ones used for the official distribution packages, and do not allow pre-built binaries or proprietary software. The model for Copr, OBS, and PPAs is that a user creates a project under their own user namespace; users have to add each repository from one of those services separately.

For example, niri creator Ivan Molodetskikh maintains a Copr repository for Fedora users who want to run the tiling Wayland compositor. To install niri from Copr, a user has to enable that repository specifically. It is possible for other Copr users to create a similar project under their own namespace, but it is not possible for another user to take over Molodetskikh's repository unless they compromise his credentials. A would-be attacker could create a malicious fork on Copr and try to lure Fedora users to add that package repository to their system instead, but the attacker cannot simply pick up an orphaned Copr repository to compromise users who have already added it.

The AUR, on the other hand, is much more relaxed about ownership; the PKGBUILD files are all maintained under the AUR namespace. The rules state that, when a new maintainer takes over an AUR package, they are supposed to add their own information as maintainer and then list the prior maintainers as contributors. That, however, is taken on trust and (as seen with the current attack) can be easily abused.