Even without computers we can use crypto if we have smartphones but we can't use it if there's no internet.
We can't fully eliminate fiats, this is the truth for now because of the modern technologies that are emerging.
People can't decide on what they can trust and use but for us crypto rocks!
This is relevant to the most extreme edges of crypto in places like east Africa I think crypto standards are used across mobile phones and also maybe a FIAT standard. With no good banking system available in those basic economies the ability to exchange value normal falls to US dollars and paper exchange, these are the people most remote from QE and Washington money printing and who ultimately pay the greatest inflation I think.
Its very possible crypto can be used still in these cases but it would rely on peer to peer networks so perhaps with great latency to a real internet confirmation of the transaction. Its possible alternate crypto standards are doing the most work in these cases.
The greatest growth possible comes from the smallest elements like this imo, very relevant to crypto future imo