Yes they do change, but they do so slowly over time.

The main issue was how jarring the change felt and how wierd it was that your leader was some famous person that’s not connected to your civ. You are essentially playing Gandhi that is leading the mayas just to then change into England one turn later.

Each banking app usually has a separate password you have to set and every transaction requires some form of authorisation.

You could make an argument about security concerns in regards to biometric scanners in phones, but short passwords are a universal thing for people that dont care.