Money is just an effective way of exchanging goods and services. It's better than trading chickens for medicine or whatever, because what if you're sick but the doctor really can't do anything with your dumb chickens.
I mean, arguments against money are juvenile. People need incentives to work. Getting rewarded for that work is an incentive. Until machines can do virtually everything humans don't want to do we need money to get them to do stuff.
That said, at some point money will be digital I'm sure, carried only on cards.