>>712970657 (OP)The economy is already moving there
Memecoin is only a few steps removed from credits. The basic structure is already there, and they're mostly called "coin" because it's weird autistic psychos trying to float them instead of normal people, who are going to stop calling them "coin" the moment they enter standard use. What they end up calling them, I don't know, but credits are more likely than coins. Slang currency terms will likely continue to be used as well. Bucks ain't going anywhere.
The other major (inevitable) shift is your several dozen, unregulated memecoins being supplanted in their entirety by one or two major, stable alternatives, held by backers everyone can trust, spendable at denominations that average people can actually use.
And then there's science fiction element is just getting value interchangability across cultures with fundamentally different values, to prevent scamming the species addicted to gold, by the species who shits it, or whatever the case may be, but most settings don't bother getting into that anyways.