And then there's the environmental problem. The environmental problem? Aren't we talking about digital coins? Yes, which makes it even stranger. Solving all those complex puzzles requires a huge amount of energy. So much energy that the two biggest blockchains in the world -- bitcoin and Ethereum -- are now using up the same amount of electricity as the whole of Austria. Carrying out a payment with Visa requires about 0.002 kilowatt-hours; the same payment with bitcoin uses up 906 kilowatt-hours, more than half a million times as much, and enough to power a two-person household for about three months.
And the environmental problem is only going to grow. As miners put more effort into solving the puzzles (ie, building more of those dark server caves in Alaska), the puzzles will automatically become more difficult, requiring more calculation power. It's an endless, pointless arms race in order to facilitate the same number of transactions with more and more energy.
Bitcoin and Ethereum use the same amount of energy as the whole of Austria: