My alternative is not some cryptocurrency. I would be happy if credit cards moved to a system where I get a message requesting a charge and I reply to authorize it. Also cash is pretty much a push system, you hand the money to the store instead of telling them where your pocket is and letting them pick what they need. Unfortunately that doesn't work online.
I imagine your alternative is some cryptocurrency that becomes worthless as soon as people stop running the nodes. Yeah, that definitely has less risk than a legal financial entity backed by the United States Government.