You would be right if the business case to create Bitcoin didn’t automatically seek out the very cheapest form of energy, which comes from the only source of it, the sun.
Now it has to be said that a much bigger portion of it than is admitted, is driven by solar power, as it needn’t be declared much for tax purposes if it isn’t connected to any power grid, and that proportion is growing all the time.
So ever increasing amounts of fiat money-as-debt are being exchanged for money-as-sunlight.
So the world economy is no longer a closed box.
Now the world economy is expanding, being pumped up by money-as-sunlight, besides the traditional capital which was always there.
The constantly increasing average market value of Bitcoin is something we have to interpret as a kind of democracy.
We want money-as-sunlight more than we want capital.
Therefore capital is deflating in our estimation, relative to Bitcoin.
In effect, we are voting for free money, because the energy of the sun, which is creating part of the money, is free.
So for the first time in history our economy, at least part of it, is connected to the power of the sun, being driven directly by that, and that part is growing all the time.
When we do the sums, we see each Bitcoin will ultimately be worth around 1MW of active solar power.

(The sums are done in my Bitcoin Kardashev Hinge story, if you wish more detail there).
Note 1MW is not a fixed amount of energy, otherwise it would be capital, it is actually a constant flow of (clean) energy received, Joules per second, so is a continuously increasing amount of energy.
Bitcoin will be unique with that incredibly useful, planet saving, and species saving property; proof of live solar power.
Still think it is a Ponzi?