The funny part is that fiat isn't going to do anything to increase your purchasing power. Bitcoin even at ~4% inflation blows fiat out of the window in terms of maintaining and increasing your purchasing power, especially over a longer period of time. On top of that, you actually use a new form of money that puts the power into the hands of the people.
In the end, even 0% inflation for Bitcoin can't prevent it from going through a lasting bear market. The speculative nature of this market is a brewing pot for boom and bust cycles. People love to buy what is going up, but dump everything they have when they see the price go down, or ignore the asset in case they don't have any holdings. That's how markets in general are.
Good thing about fiat inflation is that it gives people more incentive to spend it, or buy something like Bitcoin.