Well, fiat currency is just IOU’s, literally. Check out Debt the First 5000 Years for an anthropological look at the origins of money.

So would I prefer to live in a moneyless (i.e., debtless) post-scarcity anarchist utopia? Of course I would! Incidentally, that’s how small tribes and communities were organized for tens of thousands of years before the rise of nations.

Fiat currencies have a few advantages for maintaining a modern marketplace, whose purpose is to allocate scarce resources.

1. Personal debt is risky. If I issue an IOU, I might die before I can fulfill that promise. Governments are more permanent, which removes the speculative aspect of currency (at least for most purposes, though Forex trading is a thing).
2. A central bank can balance inflation and employment numbers to ameliorate the natural volatility of the market (with good regulation lol).
3. Fiat currency can be synchronized with economic productivity, avoiding the deflationary pressure that is anathema to any currency.

A few other things to clear up. Fiat transactions are infinitesimally cheap. I’m not sure whether ordinary transactions are 1000 or 100,000 times cheaper than using crypto, but the difference is gross. Just attempting to acquire crypto can take minutes and costs enormous fees. I know this from experience.

Dollars represent faith in the power of the US government to extract taxes from its population. Crypto represents nothing. It stands for nothing. “Coins” come and go, and if you’re the last one standing in the zero-sum game of musical chairs, you lose your savings. For that to happen with dollars, the US government would have to implode, which is unlikely.

Crypto is, quite possibly, the purest form of speculative trading (gambling) we have ever concocted. The only reason I don’t think it should be illegal is that I have no interest in saving people from their own cupidity and greed.