Crypto was a great idea ... when it was just an idea.
Given all the issues we have with bank transfers and wire-transfers around the world for fully legal sales, I thought that bitcoin was a great idea originally. It made bank transfers so fast and inexpensive but those features became such a criminal advantage too. So the crypto concept is good but back in the earlier days walking around town with a boy scout hat on, and an eight-inch knife in my belt was fine too.
So the problem isn't crypto, it's the way we are all behaving these days, getting emails like bitcoin_receipt.pdf.img etc.