If Bitcoin became universal that also means we live in a decentralised economy.
That would be very great, i hope i'm still alive to experience the situation.
I do not think it can happen ever because it means that country's currency will come into danger as they would like their currency to remain stronger in the world which benefits them. Thus as btc is not any country's currency it would not really help the government and thus they do not want to make it legal in their country.
But there's a chance the crypto and fiat can co-exist so this could be the best options that we can have. Decentralize vs centralize, it would be great and a win-win situation for everyone.
And for those who think that crypto will make banks obsolete, I doubt that it will happen, let's just say that central banks won't allow it but they can't really stop this emerging technology as well. So there might be some bargaining (like KYC/taxes) so I will take that anytime of the day.