What are you talking about? You should really check out how many people did buy a car for BTC. I'm not even talking about a luxury car but any car. Transactions like that are still rare because people prefer to watch their coins grow in value and spend fiat that depreciates anyway. You can put it in a savings account at 2% and all it's going to do is keep its current value. You won't gain anything because the inflation will eat up all the profits.