What would happen if someone, lets say Bob. Goes out and says "We got a problem. Previous governments have been doing too much QE. Inflation is going wild. We will now adopt Bitcoin as legal tender."
Would Bob get elected?
The moment Bob comes with the idea that adopting bitcoin as legal tender will kill inflation he will become the laughing stock of everyone and get 0.1% of all the votes. Just because you have a finite and limited number of coins doesn't mean that prices in goods will stay the same and it also doesn't guarantee you anything, not that you will always manage to bring together demand and offer. Bitcoin, fiat, or gold, no matter what you would have used you would have seen the same spikes in wood and coal prices and you would have seen the same contact growth in oil prices and energy as demand is gradually overcoming supply.
Poeple forget that the economies right now are no longer the same as in the middle ages when still inflation was present, the pace at which goods were manufactured shipped, and sold was totally different, reliance on imports was way smaller if not completely absent, people couldn't simply send tons of cargo to Asia next day if they were phoned they could get 2$ more on a kilo of cabbage there.