Well bartering and/or being self sufficient is better than relying on an external money.
Crypto currencies are digital non physical money that requires computers and networks
and electricity to exist, without its requirements, it does not exist and is not operable. It has many benefits over physical money. bitcoin will evolve and is the first and has the most worth at the moment.
its not easy to use these things so when they become easier their worth will rise.
RE: The problem with cryptocurrencies