What happens to Bitcoin if/when hyperinflation hits?

The entire world just decides to value and execute the transfer of goods in Bitcoin? The new dominating power doesn’t just make their cash system the reserve currency? We just don’t go back to gold? (I get that gold is very cumbersome but who says we don’t all just end up trading tokenized gold). Who says the new Emperor Caesar doesn’t just create his own Central Bank with an entire new fiat system starting from scratch?

My point is, as I’m evaluating the worthiness of expanding my Bitcoin investment - the hyperinflation of the US dollar is inevitable, but the alternative is not solely (and probably less than 50%) Bitcoin.