It really should be shut down for Arch’s sake.

I think it should really be split into two parts:

1. The more widely used packages should be moved to an official repository with review procedures. Perhaps the (quality) requirements can be lower, but these must be reviewed by trusted people.
2. The remaining packages should be moved to user namespaces, like the other user-package repos do. That will at least prevent (most) takeover attacks.

the CPU is never taxed, albeit undervolted with minus 30 on all cores in PBO

In case of an unstable system, the first thing I would do is disable all overclocks (including PBO, EXPO, undervolt, …)

Do you think benchmark results like these are meaningful when comparing Linux distributions?

They don’t really provide any explanation for why it should be faster than CachyOS. So I’d take their claims with a bucket or two of salt.