I recognize this will vary depending on how much you self-host, so I’m curious about the range of experiences from the few self-hosted things to the many self-hosted things.
Also how might you compare it to other maintenance of your other online systems (e.g. personal computer/phone/etc.)?
I have just been round my small setup and run an OS update, took about an hour. That includes a reboot of a dedicated server with OVH.
a pi and mini PC at home, a dedi at OVH running 2 LXC and 5 qemu vms. All deb a mix of 11 and 12.
I spend Wednesday evenings checking what updates need installing, I get an email every week from newreleases.io with software updates and run Semaphore to check on OS updates.