Right now, Mitumba in Nairobi can spin up a scrip in under an hour on his cell phone.
I liken it to the invention of a printing press. I can think of all the arguments for why the printing press wasn't that big of a deal when it happened. "Most people can't read! Who is this designed to help exactly? The only people that would be able to use it already know calligraphy, and on top of that have to learn typesetting, nobody is going to use this. All the illiterates will just go ask their bishop what the bible says. This is a solution in search of a problem"
And they'd be right, at the time. To some degree, world changing technological developments all solve a problem that only exists in the world they create. That's what makes them so foundationally transformative.
20 years ago if I wanted to create a currency, I had to press or mint metal coins, or come up with a print design that's hard to counterfeit, get a printer going, print tons of it at significant capital expenditure, then anyone I wanted to use it I'd have to face to face pull out my worthless monopoly money and try to explain to them why they should use it, probably to great amusement.
Right now, I can drop 20 bucks into ubiq or binance smart chain or whatever, then spend a few pennies of that launching a boilerplate erc20 contract, download coinomi wallet on my phone, watch the contract, and I've just created a sovereign currency. I don't even have to create a client application. Not only that, but in the same amount of time it took me to write that, I can explain to anyone how to use it if they want. Me and my family can just create some way to keep track of debts, we can create m3 money. We can settle out if we ever want to, just like you used to be able to redeem your bank notes for gold. Mitumba can create something to keep track of sorghum production in his village or whatever.
This is why this will take over the world. The ability to create financial instruments has been democratized. You might not like it, you might think it is stupid, you might have a plethora of reasons why it is a terrible idea. But the genie is out of the bottle, and over the coming decades you're going to begin to see lists on the front of lemonade stands telling you what currencies are accepted. Maybe Juan who owns the taco truck gives you a discount for paying him in bobcoin for some probably stupid reason or another. The day is coming where you'll be more likely to pay in some random cryptocurrency or other for random purchases than in a state currency, if for no other reason because the ease with which a person can create a currency is ridiculous today, so the world will be drowning in them.
If you want to trade digital trading cards, great. If you want to pay with Euros or Pesos, or DogeCoin, instead of US Dollars, also great, go ahead. But don't pretend that minting your own coin for your family is a use case that was impossible to do with Google docs, or even with a piece of paper and pen.
I can mint a token right now with minimal expenditure that cannot be counterfeited that anyone in the world can use to represent exchange of value. And everyone in the world can also do that. You could not do that with google docs. It is not the same thing as barter.
Again, and my main point: you might think that it is stupid, a terrible idea, and you might even be right, but because anyone can do it, it isn't going away. This is the world now.
I'm saying that if you want to create a way to track what each person in a family owes each other you have been able to do that with with google docs for years. Or you could use a pen and paper to create a family ledger, if you were worried about counterfeiting or your house burning down, put it in a fire proof safe.
First, it is easier to ensure integrity of the ledger using cryptocurrency than it is keeping a canonical double spaced piece of notebook paper, and second, it is as easy to do it for my family as Mitumba for his village or a group of 1000 random people on some forum. Anyone can spin up a secure currency for any purpose with minimal cost and effort.
20 years ago only big companies could do it. Now anyone can do it, so they will. There are over 15,000 cryptocurrencies of one kind or another right now. When anyone can spin one up for peanuts lots of people will.
Furthermore, if you were in the United States and found any success in this, you would be arrested and charged under 18 USC 486: https://www.law.cornell.edu/uscode/text/18/486
Not so with cryptocurrency, for some reason.