That’s a nice thought OP.
But if we see practically than it’s not possible.
Bitcoin is a digital currency/asset. It’s not a paper cash.
As assets were earlier used to given more importance in barter system, and yes that time BTC might became the national currency.
But at current point of time, thinking this about Bitcoin becoming as a national currency makes me laugh.
But still as future is unpredictable, anything can really happen.