The 2020 Air I inherited from my daughter had met with a beverage at a bad time. We paid a third party to resurrect it (Apple doesn't touch wet stuff) but the machine seemed quirky in a software way. Maybe related to the T2 chip and doing the battery swap and then (mistake) Migration Assistant from my ancient Air.
First I had to fix the VoiceTrigger bug, but the machine was slow and I kept running into weird sh*t, like being unable to enable the default App Expose gesture.
So I decided to cleanup by removing files on that machine (they are still on my working Air) and also clean up the user library. I removed a lot of 2007 and earlier items, including a RAZR plug-in. Maybe did nothing but didn't take long.
Then I ran Onyx and it complained the disk was corrupted. When I tried to run Disk Utility I ran into the SMC reset bug.
Once I fixed that Disk Utility would run, but it complained about a corrupt snapshot on my Data drive. Deleting the snapshot didn't fix the error though, so it's likely a red herring. The message said to run fsck on the Container, but I didn't see how to do that. Running it on the Volume didn't help.
The Disk Utility directions were, of course, wrong. As were various web sites that said to try fsck in single user mode (is single user even possible in Monterey?).
Eclectic Light had the best guidance, but the real missing piece was telling Disk Utility to show everyone, not just Volumes. That showed me the Container so I could run DU there; the details console shows it's running fsck_apfs -y -x /dev/disk0s2. It ran against all the /dev/disk* things and fixed them all, exiting successfully. My App Expose gesture returned.
I think the demons are purged for now. macOS is pretty damn fragile these days ...