I don't think that's generally true. It is very useful for criminals in countries that don't extradite to the US, but
Many of those same people could make and were making money through other forms of cybercrime for years. Even without cryptocurrencies, new technology will always keep coming out that'll facilitate and potentiate more cybercrime.
To me, the answer there is and has to be geopolitical. Whatever crime they're committing, if it's against a foreign national, they have zero fear of repercussions, and that lack of fear is totally rational because there's basically no chance they'll ever face repercussions even if their real name and address is plastered in a million places. If they knew they could be extradited, or at least sentenced to serious prison time in their own country, and that there was a significant chance of it happening if they were to be identified, then I'm convinced most of them would behave differently.