I know plenty. But not among the 18-20 year olds that do not know it any different, sure. But certainly my grandpa. Just thinking that you do not need a power-bank and just bring an extra battery on a longer trip will get millions of people interested.

I struggle to see the difference between "bringing an extra battery" and "bringing a power bank".

Except that the latter has more functionality than the former, and should be prefereable.