Ok let’s replace price with purchasing power.

Bitcoin is volatile in terms of purchasing power, given that it is not in itself a unit of account.

I buy $60 of bitcoin today. I want to spend it tomorrow on groceries. The price of BTC went down and my $60 are now only worth $50. This is a consistent pattern. I don’t have day to day purchasing power stability.

I am talking about relatively short time frames given that we are talking about the use case of bitcoin as a practical way to transact on a daily basis.