Cash you can e-mail was a great idea.
Wiggly-line arbitrage makes it completely fucking useless.
Proof of whatever won't change how finance bros ruined this. They didn't create it or make it real. They broke a cool new technology, for profit. You can't buy things with it. It's not really currency. It's just you assholes juggling tulip-bulbs, and occasionally exchanging one for a nice car or an ugly house.
The straightforward fix is inflation. Make line go down, and you can hand out fake cash willy-nilly. The finance-bro crowd understands this (or think they do) but view it as a bug rather than a feature, because then how do I get rich sitting on my thumb? "You don't" is the necessary answer, for currency. Currency is not an investment. The value of currency is exchange. If you're measuring liquidity in terms of trading two things back and forth, that's not economic activity, that's masturbation.
But you can give people digital bottlecaps or whateverthefuck, and so long as they're broadly well-distributed, people will throw them at podcasts and weird porn or whatever, and gradually accumulate value where people do things and make stuff. Even if it's just weird porn. If the value per-widget is low and falling, that's all the more reason to get it out of your pocket. It will find its way through interfaces into the real world. Not for houses and cars, but for things regular people buy regularly.
Which remains important, because PayPal is still the devil.