I think a legitimate downside to blockchain is privacy. Sure, Stripe can (try to) prevent you from buying marijuana, but with crypto you’re required to announce that you’ve bought something from Dr. Chronic on the public ledger. Doesn’t that create an opportunity for discrimination/censorship/prosecution post-purchase? At least with Visa, you have a reasonable expectation that the transaction is private between you and the merchant. If you actually made the majority of your purchases on a blockchain, you’re publicizing a ton of information about yourself.