From experience, I highly doubt it was actually unrecoverable. I did something similar many times & all it takes is to read archlinux.org news section & apply .pacnew config diffs where needed. Arch is a bleeding edge distro constantly marching ahead; that's one of its primary advantages, so it's best to update regularly. That being said it is very much possible to not update for months, just requires a bit of extra care when you finally do due to the large number of accumulated changes.

I even did an online, in place switchover from SysV to systemd in 2011 and despite that being a scary amount of changes at once still got a working system.

The trade off there is that Apple can then perform a major architectural shift in a single fell swoop because it’s not carrying around silly amounts of legacy cruft. Endless backwards compatibility isn’t always a benefit imo.

The latter. Usually when my Microsoft Surface Book 2 (the flagship consumer device, for context) BSODs for the third time in a day because MS couldn't be assed to fix compatibility/thermal issues with the graphics card that was one of the highlight features of the device, or the tablet undocking (another highlight feature) fails, or their "Modern Standby" drains the battery from 100% to 0% overnight (Is it the 3AM wake-up to phone home? Weird ancient USB controller issues? Who knows!), I tend to just go to reddit or the Microsoft support forums and see how many other people are complaining without finding any solutions. No time to blog.

My new Mac mini was doing kernel panics at every shutdown for about a year.

The 4th "security update" somehow made that disappear?!