I can’t remember exactly when macOS made the change. It was a few years back.
>The system domain contains the system software installed by Apple. The resources in the system domain are required by the system to run. Users cannot add, remove, or alter items in this domain.
I’m sure it’s still possible to junk a system up, but a user shouldn’t be able to screw up the actual system files.
/Library is probably the biggest wildcard, as it impacts all users on the system, otherwise, creating a new user account should clean up pretty much everything, without having to reinstall the OS itself. I assume making a normal user account for the persons could allow the admin the ability to prevent the user from adding things to /Applications and /Library. The user would still be able to install apps using a ~/Applications folder and have settings in ~/Library. ~/Library is typically used automatically, while ~/Applications is something that needs to be created, but works just fine. I use this at work to install some things I would otherwise not be able to install.
>The system domain contains the system software installed by Apple. The resources in the system domain are required by the system to run. Users cannot add, remove, or alter items in this domain.
https://developer.apple.com/library/archive/documentation/Fi...
I’m sure it’s still possible to junk a system up, but a user shouldn’t be able to screw up the actual system files.
/Library is probably the biggest wildcard, as it impacts all users on the system, otherwise, creating a new user account should clean up pretty much everything, without having to reinstall the OS itself. I assume making a normal user account for the persons could allow the admin the ability to prevent the user from adding things to /Applications and /Library. The user would still be able to install apps using a ~/Applications folder and have settings in ~/Library. ~/Library is typically used automatically, while ~/Applications is something that needs to be created, but works just fine. I use this at work to install some things I would otherwise not be able to install.