Great last name, but I differ on a few points.

Take a paper currency out of your wallet, who issued it? If its a US Dollar, it wasn't the US government that issued it. Why is a dollar worth a dollar? Because you can trade it for something, you can trade cryptos also. What guarentees the dollar is valid, frankly men with guns do, make your own dollar and you'll get a visit. With cryptos, the crypto part of it subsitutes for the men with guns part. Bitcoin is not a good trading currency, other cryptos are better suited for trading. And yeah, things are volitile right now, and if some currencies don't settle down, that will be an issue. But, the US dollar varies as well, against other currencies. It floats relative to our countries worth so to speak. There are digital wallet apps that make paying with crypto just like apple pay, goggle pay and samsung pay.