But what exactly are you protecting then?
Linux root/regular-user model comes from an ancient time with multi-user architecture where you defended against one user taking over a big machine they didn't own.
But today on personal computers all the good stuff is inside regular users accounts, and there is nothing valuable to be gained by becoming root.
So the whole security model is broken, it protects the OS system files that nobody cares about, while allowing any piece of software complete access to valuable user files.
Well you of course want to sub-divide every application in user space either with gvisor or a hypervisor, like QubesOS.
If someone pwns your personal browser they should pop out into an environment where nothing exists but that browser, with no idea the work browser is in a sibling vm.