Today, knowing both worlds, it is the only currency that I trust, it is the only system that I trust and I will dedicate my life to carry this forward. Bitcoin forever.
But you're still need to use fiat because you can't use Bitcoin to pay anything in your country, so you're still trusting fiat even you're not use it as to store your wealth. We might see a big change when CBDC has been launched by the government, it's either they will ban Bitcoin or they still consider to accept it. But you can still use Bitcoin since there's a way to trade Bitcoin without need a permission from centralized entity, as long as you not make any mistake.
Someone using fiat does not automatically translate that they trust the fiat system. He can be using fiat because it is what the government of his economy permits and that does not mean that he trusts fiat.
Even the government knows that the system of currency they operate has been flawed. What they do is fight tirelessly to make sure that the rising technology of Bitcoin and crypto graphy is being eliminated, but that is what they cannot achieve.
It is clearly obvious that the world financial system is going to change in a few decades to come and we are lucky we have already taken the early spot in the market.