What are you on about? Accelerating global warming so that I can own a reference to a hyperlink to a JPG of a monkey wearing a top hat is absolutely a fantastic use case for blockchain!
To be fair, there are plans for a (international) bank exchange system based on Blockchain. Right now it's either things like "Swift", trust, or physically shipping gold.
Blockchain allows for a system where they just have to trust the system, as a whole, and not individual banks, or the governments above them.
This is the only useful use for block chain I've seen, that isn't better served in another way.
There's generally significant trust between national level banks. So long as they have some sort of trust in the countries involved, it can't be intercepted by a 3rd country.
There's plenty of uses for blockchains, but it's almost all about document validation and contract non-repudiation (boring bureaucratic things), not so much for commodities ("currency") and copyright enforcement (NFTs).
Blockchain DNS seems like a good idea some days, but other days the entirety of the internet seems like a huge mistake.
There are uses for blockchain for internal company ledgers on a small scale. its just the standard style with crypto that is only useful for global warming.
There are uses for 'blockchain' based systems, for instance git uses what is effectively a blockchain to store commits. The big difference is, rather than using proof-of-work or proof-of-funds to maintain consistently, if you break the upstream repository 'Mad' Dave over there, who is trying to push his changes before the weekend will beat you with an Ethernet cable until you regret your ways.
Why would you want blockchain for making illegal purchases? Crypto makes sense as a non fiat currency. But blockchain is an non alterable record.