That’s a perspective on the AUR that I hadn’t really seen before from Arch advocates, in my (admittedly hazy memory) it’s usually mentioned in the sense of “Arch is great because you always get the latest packages in the official repos and basically anything you possibly need you can just install from the AUR”. If you’re actually using it just as a reference guide essentially then it seems like there’s some value there.

However, I’ll push back a bit from my perspective as a Debian Stable user. I would consider even the official Arch repositories to be dangerous just like I consider Debian Sid’s repos to be dangerous (packages are too new and not sufficiently vetted). Then regarding installing packages not available in the main Debian repos, I’ve never really had any issues installing them either as there is always either an official developer run apt repo I can add, or an official deb package, or it just builds directly from official source without tweaks. So I’ve honestly never felt like I was missing “a crowdsourced set of people’s tips and tricks for installing stuff” on Debian as I’ve just never needed one.

I do realize that installing the latest packages directly from a developer’s repo or latest deb package or source is as dangerous as the Debian Sid or Arch official repos for the same reason (too new, not vetted), but the difference is those are only a tiny portion of the packages installed on my system (like a percent of a percent, maybe a half dozen packages out of hundreds). If I ran Sid or Arch, it would be 100% of the packages on my system which is an attack surface orders of magnitude larger.

EDIT: It did just occur to me after posting this reply that I use Homebrew pretty extensively as a package manager on macOS and its official repos are equivalent to Sid/Arch official repos, so I may be a bit of a hypocrite here :P