It's not because of the USD price. Sats trade in hundreds of currency pairs and Thousands crypto pairs and real world goods. There was a time where two pizzas = 10,000 BTC and there was no fiat price.

All prices everywhere are determined by supply and demand, fiat has nothing to do with it. If they printed trillions more USD, the Monero/sats pair probably wouldn't move that much even tho the USD/sats pair would move a lot