No central group or ruler mandates Bitcoin’s value be pegged in any way to anything. It trades against electricity at prices set by a hard-coded computer program and the free market. Bitcoin is not fiat. You will not suffer at the hands of any tyrant if you choose not to adopt it.
There is an electricity cost for the computation of the next Bitcoin block. As long as there is demand for for space in the next Bitcoin block, there will be a demand for that computation. So as long as there is demand for blockspace, there will be some electricity value of bitcoin. And as long as electricity is a real commodity in the real world, this Bitcoin/electricity price can be converted to a Bitcoin price for other commodities in the real world.
As long as fiat currency is a real commodity in the real world, there will be a Bitcoin/fiat price. But if fiat becomes worthless, the Bitcoin/fiat price will go to infinity.
Bitcoin will still have its BTC/electricity price. And since gold will still have value relative to electricity, there will still be a BTC/Gold price. And a BTC/chicken price. A BTC/oil price and so on.
You’re hung up on Bitcoin’s price in fiat as if that is the only exchange rate it has. In fact, it’s exchangeable for literally anything by virtue of its floating peg to energy, which is the real liquid universal commodity.