That's perhaps the intent ideally, but in practice, it feels like AUR tends to be (a) niche, esoteric things that will never be anywhere outside of AUR, even if they could, or (b) installation methods for proprietary/otherwise non-open packages that can't be.
The latter seems to a major popular use of AUR: sorting packages by popularity or votes comes up with lists that seem to be mostly these. And that's likely a significant draw for non-technical users. If you want to install things like Dropbox, Chrome, VS Code, Minecraft, Zoom, Slack... they all show up in AUR. By their nature (usually extracting packages from upstream installation methods), they tend to be more complicated than generic AUR packages. They are also often quite a bit more convenient than using the upstream packages, which might not interface well with Archlinux, might only be available with installation methods that clobber things, might be deb/rpm only, etc.
I wonder if it would make sense to have a more trusted/vetted repository of these sorts of scripts, separate from core repositories but also not as free-for-all as AUR. That might go a long way toward keeping non-technical users from being drawn to AUR.