There is no cantillionair effect with bitcoin. If you have a lot of bitcoin, you will be Fiat rich but anyone with bitcoin will be over time, but in a bitcoin only world having a lot of bitcoin will only last for so long, you will have to continue to provide value to get btc.
Discussion
I already explained that deflation means that you can maintain your relative purchasing power while spending.
Wealth is not nominal; it changes with the purchasing power of your money.