I WAS holding off on Monterey because reports were that the map update software for my car navigation system was unable to see the USB drive to build the update. Someone with the same car then said they had it working, so I went and updated. Apparently it works fine on M1 Macs but not on Intel Macs so now I can't build the update drive (next time one comes out, I did one right before updating my Mac) unless I build a USB stick to boot Big Sur or they update the software to work properly.
and of course, as I go to verify this I see there's an update to the map downloader app and it seems to be able to access the USB drive! So, no, I don't have a need for an older OS now...