I recall the AUR always being touted very highly as some great advantage for Arch as a linux distro, unfortunately this convenience has also come with a price.
It's crazy that all it takes to become a maintainer of a package is to flag it as orphaned, wait 2 weeks for the original maintainer to fail to respond because they're on a holiday, and BAM! - the attacker can gets assigned as a maintainer and can now ship spicy updates.
That is a terrible way to run a package repo in this day and age.
Maintainers need to have some level of vetting, and should own a repo or three for a while to establish a track record, before they get to blast out contributions to 100 of them without any review.