Crypto is a good alternative but will only remain as an alternative since the main money in this world will always be fiat.
There are people who believe on the possibility that crypto will replace fiat, but are we big enough to replace them or do we have the support from the government to make it happen, whether we like it or not, we are all under the control of the government.
Please notice that the acceleration of changes our world is undergoing currently is higher than ever today. I would agree with you if the world was going forward with the same pace as before, but this is not the case. Through the whole history of humankind there were no such period of time as the last 30 years when so many unpredictable things have happened. I mean the appearance of the Internet that is currently used by 3.2 billion people and the appearance of smartphones (currently used by 2.7 billion people). I bet in 10 years most of the governments will be so unlike the current ones, we can't even imagine. And there is a chance that those new governments will be preferring crypto over fiat.
That was really ambitious though but I don't really think it's possible.
Maybe I need to educate myself more to see its possibility, we the government changes their laws and policy but one hindrance is their interest.
If ever maybe we will have a clean government which is close to impossible, we might enjoy a transparent currency like bitcoin.
Bitcoin is not scalable according to some, but we have a good solution to that which is the lightning network and that makes it good for adoption.
My only concern which is the government in general, they want control and their control will be eliminated or will reduce as fiat will be replace with crypto.