We don't know, maybe even Satoshi the founder has a narrative like that. You know, the reason why he creates a BTC is because maybe he hates fiat and wants to replace it by his own creation but if not, there might still be people who can think like that. BTC have already gone a long way, so why not right? Maybe we are truly heading on that direction?
But even right now or even before, we still can use our BTC as a main currency as long as we are on a country that allows it and even if not, we still can do bypasses and shop directly online using it. BTC has an advantage but it is not perfect. It has a disadvantage too and some people can consider it, resulting for them to not totally rely on the coin.
I don't think he created bitcoin because he hated fiat because from what we see generally fiat is still a human need and even if he was still alive, he would still use fiat.
No one says it's impossible but we see in reality that currently the use of bitcoin for transaction matters is not that widespread.
If shopping online might be true because there are several places that currently facilitate purchases using bitcoin.
In the near future, this cannot be implemented globally because each country has its own currency and they will certainly maintain fiat as a means of transaction.
Back to the main discussion, whether bitcoin can save us, of course it depends on how people use bitcoin and if someone wants to achieve financial freedom then invest in bitcoin consistently.