So I’m trying to understand if you think that shutting down an update during regenerating the initramfs indicates that Arch isn’t stable? Because that’s a FAFO move and would crater any non-atomic update distro.

When talking about Linux, “stable” usually means “doesn’t have major changes often”, or in other words, “doesn’t have lots of updates that break stuff”. That’s why “Debian stable” is called that. Arch is not that.

Stable does not mean it’s for everybody. My installation runs since now 10 years.

(The only other distribution this failsafe I know of is Debian)

It is! My Desktop hardly ever topples over!