Appliances serve clear purposes for the entire population. I am yet to here of a meaningful Bitcoin purpose, even for the small handful of “investors.”

Well, here's a meaningful purpose by yours truly. I live in Spain and in Argentina. I have to regularly send money to Argentina. International transfers to Argentina are really expensive. Also, in Argentina the currency exchange is being manipulated by the government, like what happens in Venezuela. And all transfers have to be at the exchange rate dictated by the government.

Except for crypto currencies. They operate in a grey market, not forbidden, not approved.

Without bitcoin, I'd have to transfer money at the oficial rate, and I'd have to have another person on the other side filling the endless paperwork they require. With bitcoin (litecoin nowadays, cheaper transactions) it's done in a few hours.

> Proof of work? The entire worldwide bitcoin network uses less power that all the appliances in stand-by mode just in America, and I still have to see someone complaining about how wasteful stand-by mode is.

We've spent tons of money and had massive amounts of regulation and standards over the past couple of decades to try and reduce standby power. It's presently estimated at 5-10% of US power, versus 10-20% a couple decades ago. A relatively big share of it is very old devices.

I'm not opposed to distributed ledgers. Proof of stake will be augmented to provide nearly the same level of guarantee as proof of work, without all the power draw.