Bitcoin can change depending on the need of the users, assuming it's something accepted by them, which sounds fair to me.

As for the inflation/fiat it just seems to me that you keep ignoring the possibility of a failure of such system. A failure of such system would for sure have terrible consequences and the poor unlike the wealthier will have harder times. Investing the fiat is a good idea, not something remotely popular in my country alas. Here, saving mostly means saving money at the bank (which devalues over time). No wonder why they feel they're losing purchasing power. People who work shall earn wealth simply put, not diminished wealth if they don't learn about financial tricks from someone they trust.