I get what you're saying of course, but as a fun counterpoint, I gave my brother $50 worth of Monero for Christmas and he has absolutely no idea how cryptocurrencies work, had never heard of Monero. I simply wrote out instructions on a piece of paper, the seed, basic opsec, and there you go. He probably put it in his drawer and forgot about it. But he'll remember and learn how it works real quick if I ever tell him it's at $50,000 or something in a few years haha.
That doesn't sound like a cash replacement to me, it sounds like an investment vehicle. The reason cash is cash is that there's no inherent benefit to sitting on it. No one is going to be able to trade 10 $5 bills they put in the drawer this year for 5 $100 bills in a year or two, and we all understand that and operate on that shared understanding. If there's a hope and a real chance that I could get rich by just sitting on a cryptocurrency, I'll have to weigh its divestment against holding it. And the people or entities that have the biggest counterweight to investment are likely to be those who get some additional benefit besides its monetary value that they'd have to pay mightily for with cash anyway, like anonymity for practical rather than political reasons.
