> The way Unix works, a directory is a file, so if you can write in a directory you'll also be able to move directories around

Well, maybe this should be changed, or we could just use the sticky bit.

Other users, except for primary user, can use /ubuntu24/home/. Primary user uses the root of hard drive however they want.

> because it'll also search all the other system subdirectories too.

It's already a pain because /home contains lots of system files, caches etc. And it would not be difficult to add a flag "skip system files".