You say "the" government like there's only one. These platforms enable multilateral interoperation by default. In the fiat world, each government currency exist

You say "the" government like there's only one. These platforms enable multilateral interoperation by default. In the fiat world, each government currency exists in its own central-bank database. In a crypto world, the US-gov-backed USD stablecoin and the EU-backed Euro stablecoin would exist on the same blockchain. Also, you seem to be thinking like currencies (whether fiat securities, or decentralized autonomous securities) are the central point — or only point — of blockchains. This is true of "ledger-only" blockchains like Bitcoin — which is why I say those would be mostly irrelevant. But in decentralized-computation platforms like Ethereum, there are lots of other things going on; and I'm not suggesting to limit any of that stuff to only fiat/regulated use-cases. My argument is against cryptocurrencies (decentralized autonomous securities) specifically; not against utility tokens, governance tokens, DAOs, virtual pets, or anything else people do with blockchains. All that stuff is inherently global — and it would make no sense to have to "shard" the state of any of it onto into separate ledgers per legal regime. The legal regimes can come to the distributed computer, not the other way around.