Earlier quoted context omitted.
As much as they need for what? Aside of ransom payments and drugs, you don't need to buy cryptocurrency, ordinary fiat money works just fine as a medium of transfer.
This is a very privileged, first-world perspective on things. You probably have a checking account, and a debit card. If you only have cash, and want to send money to (for example) family in another country, it gets very expensive, very fast. Exchanging cash for cryptocurrency without a bank inbetween is a pain in the ass, but its a hell of a lot cheaper than, for example, Western Union.
I live in Mexico, I don't know if we're first world or not. We're kind of in between. We have bank accounts and debit cards here too. In the past when I wanted to send cash to the US or vice versa, I've used Western Union for the convenience - the local corner store (which in Mexico will be Oxxo or 711) has western union. When my family here in MX needs money, I just transfer it to their bank account via my bank's app.
I think many people in the US overestimate how privileged they are compared to most of the rest of the world, to be honest. I lived in the US when I was young but left because life felt easier here in MX.
Sorry for this kind of ambling response, I don't really disagree with anything you said, your perspective just piqued my interest :)