

Oddly, millionaires aren’t really the middle class. House’s in California routinely cost more than a million dollars. And a lot of people probably have a million dollars of retirement in one form or another. (Pensions have a value that very often tops a million). The middle class you are describing (athletes and pop stars) probably are more like 100 million or something. We just don’t have a good name for that.
Actually, what is hard about changing banks? I give my bank info to as few entities as possible. And almost all of them would take a few clicks and possibly a few days to verify some tiny transaction and I would be done. Changing credit cards is far harder. But also. Why are you using the banks app on your phone. That phone is probably the least secure electronic you own. The attack surface on that thing is absolutely huge.