Is it useful for people in countries with shitty governments? Very much so, it seems to me. Which is great. But that is not an argument for its intrinsic value as opposed to normal currency in a country with a functioning economy and government.
Mycorrhizal networks, to pick just one of myriad counterexamples, would like a word. Decentralization is just something that humans are (so far) bad at designing for.
> paying with crypto is always going to be more painful [than fiat] unless you use an exchange
Always is a long time. As governments figure out how to add features to fiat via CBDC's I can definitely image some bloat that would make paying in fiat needlessly complex. It's not like cryptocurrency has the market cornered on bad decisions.