USD maintains its store of value by the interest rate (they just print or burn)

But it's purchasing power, well that's the real thing.

Bitcoin isn't a store of value, if you "stored your value" at 124k, where are you now?

So it's not. It's just a currency, priced at a whatever it's demand for that currency is. Similarly, less central banks hold dollars because the demand for dollars has declined.

You can say Bitcoin's purchasing power increases over time, that's a better understanding than calling it a store of value.