I think one also has to weigh the possibility of some kind of disaster occuring doing a backup-wipe-clean install vs just an upgrade install. It’s non-zero and that’s enough for most people.

I just retired after 20+ years at Apple working on the OS X kernel and I do the upgrades both ways but I don’t have a strong feeling for one over the other. I usually just upgrade install, especially since drives are huge these days and I’m not often tight on disk space.