> sensible to store information relevant only to this OS in a specific cache somewhere within that OS.

For most of these files, this isn’t information that can be reconstructed, so caching isn’t an option.

Also, the information has to move with the disk, if it is moved to or mounted on another system.

There are some tradeoffs. Like if you used a usb and set up folder colours or any of the other things stored in the file, they would not move along with the usb when used on another computer.