[jrumbut]

You could probably say the same about any operating system, especially if you exclude the same human user operating in multiple roles.

Though in the Unix environment, additional user accounts and groups that don't actually correspond to separate humans have a lot of pragmatic uses.

[pjmlp]

Yes, however that wasn't a relevant feature for 1980-90's workstation market, like under which user the printer daemon would be running under.