The packages on the AUR are all user created. It's not really comparable to the Microsoft Store.

The Windows equivalent of this would basically be the discovery that a bunch of apps on the Microsoft Store were infected with malware.

You mean like this?

https://www.howtogeek.com/788382/beware-of-malware-in-windows-apps-on-the-microsoft-store/

There is a reason why the arch community had such a bad reputation when it came to newcomers, they were gate keeping good technical knowledge of the system. It had the side effect that most people became royal dicks on the forums and stopped being helpful, but it did have what I would consider the intended effect of people being wary of everything they did on their system.

I find the easy arch distros to be fairly interesting since my recommendation has always been that anyone who wants to daily drive an arch distro should install arch through command line at least once and read about the packages they use. I personally run endeavor os, but I started by doing the leg work, which led me to the conclusion that I prefer flatpaks over aur if it is available because they are far more easier to maintain good security practices on.

CachyOS is completely 100% unaffected UNLESS people chose to install applications from the AUR.