@Ruthford China doesn't like permission-less blockchains. There are a few state-backed permissioned blockchains including NFT platforms ("digital collectables") and they are required to use fiat currency:
"The question we now have to ask is, if technologically it is possible to make an impenetrable device or system, where the encryption is so strong that there’s no key, there’s no door at all, then how do we apprehend the child pornographer, how do we solve or disrupt a terrorist plot? What mechanisms do we have available to even do simple things like tax enforcement? Because if, in fact, you can’t crack that at all, government can’t get in, then everybody’s walking around with a Swiss bank account in their pocket”