If everyone is unmasked and the Omicron variant seems to burn through the vaccines in terms of infection but not serious illness, does that mean that it can lead to more mutations and more _bad_ mutations if so many people get it? What's the "mutation rate" in a person who has mild or no symptoms and how infectious are they?

It just seems if one sick person creates a bad variant that is more infectious or even more deadly (and burn through the vaccines like Omicron) and everyone is unmasked/etc at the same time then such a variant could spread wide without immediate detection. I have no idea if any of this is true so take it with a grain of salt...