Some cryptos are anonymous, like Monero. Most times scammers get caught because they slipped up somewhere in the past that connects the dots to them. Or they are good at scamming but not very knowledgeable about crypto technicalities.
Crypto as a concept has its function, we are just at the infant stage of adoption where making a quick buck is the aim. There are tons of real life application project out there but obviously no one gives a $hit about that as it's not sexy.