bitcoin is a netscape of digital currencies. there will be more advanced central bank coin in the future with regular people mass adoption which you can actually use at grocery store
IMO that is practically irrelevant.
Gold exists and it's not an accepted form of money, but almost exclusively used as a safe haven asset. There is $8 TRILLION invested in Gold.
If people use FiatCoin in the future there is still a case for an alternative safe haven crypto asset (BTC). If BTC reaches 2% of Gold market cap then we're at $10,000 BTC.