[Shatnerz]

Bitcoin may not be the best example because it does have a lot of limitation and somewhat failed as a currency and instead turned into a speculative store of value. Block time on Bitcoin is ~10 min. For small purchases, you would probably be fine with 1 confirmation, but a 10 minute wait is terrible UX. There is lighting which is a layer on top of bitcoin which is much faster, but the UX is still a bit clunky.

But in general, I agree that cryptocurrencies could help the problem, but it still carries the compliance and AML risks unless you can outsource that to a 3rd party. What happens if you accept funds from an OFAC or other sanctioned account? Violating AML can come with huge fines and is generally just a massive headache. Cash doesn't have these issues as the evidence is generally impossible to track well. With nearly all cryptocurrencies, the entire ledger is open, so if you accidentally accepted payment from the wrong person, you could get royally screwed at some later time.