But it's fine that white protagonists are over saturated?
No? But a white protagonist isn't inherently bad.
The correct thing to do would be to implement non-white protagonists (which we have a lot of, just need more) but not count having a white protagonist as a black mark against the work of fiction.
Tbh, we shouldn't care what race the protagonist of a work of fiction is anyways, as the race of a main character doesn't have an impact on the work they appear in's quality.
Tldr: It would be nice to have diversity, but a white protagonist should not count against the quality of a work of fiction.