Yeah, the problem with all the arguments I've seen for the existence of midlevels is that once you give them an inch, they inevitably take a mile. Well, outside of surgery/DR, at least.
Midlevels are a solution for a problem that was manufactured by worthless administrators, as usual. Force doctors to see more patients at all costs, and then throw midlevels at them when they can't keep up or meet your completely unreasonable demands, devaluing doctors in the process. It's a win-win for these people.
Alas, that ship has sailed, so we can only do what we can to stop them from harming/killing patients.