being a nerd here, sudo - yes, but indeed I thought the entire UNIX design of everything is files and there are permissions, groups, etc, should be sufficient.

But I think the "new world" is, we are over stimulated (eg. agents ask us 'permissions' for a long command) so we might give a sudo not fully aware of it where a big bold UX message box after a 'pseudo' sudo would better catch our eyes.

So it seems this is about adding additional layers over already existing ones in a way?

The UNIX model assumed each human had one user. It did not provide a flexible way to sub-divide that scope for each program running as that user.

It has been extended, but not in a way that non-technical users can really use.