Of course it makes sense. Running applications as restricted users has been standard practice for decades, precisely because it makes sense.

...as a way of preventing users from interfering with the system or other users in multi user systems. Running applications as a user different from yourself is an ugly hack we've started doing because we don't have actual control over what our applications can access, so things like ransomware are possible despite not having system level access. Since Plan9 never took off, containerization of applications is the next best thing.

What I'm saying is, running in a restricted user account does absolutely nothing to protect the user running in the restricted account from malicious applciations. That's how the user/group model fails in personal computing.

* in the real life, there is “sudo hole”, but this can be fixed within the current user concept.

I was under impression that even with zero days, using modern distribution and auto updates will minimize the amount of time the system is vulnerable, so for most of time, it will be sufficient.