They lost the appeal because
1) global logistics normalized, moving the bulk of the money laundering activities back to their usual places (eg physical art),
2) people started realizing that the blockchain actually created a papertrail that’s much harder to conceal than a bunch of literal paper documents scattered across a web of global freight forwarding companies and shell companies and
3) KYC rules turned most fringe crypto exchanges into tightly monitored trading platforms
Crypto as a whole became less utilized as a laundering & gambling medium for those reasons, but it didn’t fully disappear since ETFs keep liquidity happening and transferring money with crypto is still better than swift in a lot of cases. NFTs went away because they had no use whatsoever