Crypto in theory should be very useful suffers from realities:
1. People want to use government controlled moneybdue to the stability benefits:
* Stable value in short term
* Legal system can clawback money
* Banks have anti fraud system and some level of accountability
* Security is taken care of
2. Shops don't generally take crypto, they take fiat money
Crypto therefore services the world where these disadvantages are outweighed by advantages, which is mostly going to be various illegal or quasi legal activities or simply price speculation.