Btw if you believe Bitcoin is a good investment, better than say a savings account, then go ahead buy Bitcoin. Like buying shares, real estate etc. whatever. But what does that have to do with the credit card. When you invest you don't spend and if one day you need to spend you sell assets for fiat and then spend that. Important: You don't count on having fiat and how much until you actually sell. Your day-to-day expense budgeting involves just fiat you actually have.
Because you mentioned a credit card and everyday spending it seemed you were wanting to do your expense budgeting in Bitcoin and were hoping that prices in Bitcoin would go down thanks to just fiat inflation. But if the fiat price of Bitcoin rises just thanks to inflation then Bitcoin prices of goods and services will just remain stable. So no free lunch.