[prirun]

Thanks very much! I had no idea about this, but doing a find command as root did indeed find my backup. It was at:

/System/Volumes/Data/Users/Shared/Previously Relocated Items/Security/hbbackup

I don't know how people are supposed to know this. Plus it is taking up 50GB of space!

[Aloisius]

IIRC, it should create an alias on your Desktop called Relocated Items or something similar to them after the upgrade that pointed at it.

[prirun]

Thanks! I never look at my Desktop and so never noticed it. I deleted the original, moved backup today, and there is nothing on my Desktop about Relocated Items. That could be because I removed it, like an Apple smart link thing, or maybe it was never there - dunno.

IMO, if they're going to do something this drastic, they should at least have a one-time large pop-up box after the upgrade explaining that they moved things that were formerly in root, and wait for a user to confirm that they read the notice.

[ArchOversight]

That would be unnecessary for almost every single last macOS user, you are an outlier.

If you go against the grain or the way the OS is built and explicitly disable SIP and do things the OS would normally not allow, you are expected to understand the OS enough to know where things have disappeared to when they disappear.

I don't think Apple should protect the very small minority from themselves.