>unimaginable energy waste of mining cryptocurrencies
Not all cryptocurrencies require a massive amount of energy.
>Cryptocurrencies have existed for eleven years, they should have something to show for right now
I'm using a cryptocurrency for feeless, instant microtransactions in a browser based game. It happens to be a near ideal solution. That, said I won't force it upon anyone. It is a purely voluntary proposition.
>Ponzi
This is somewhat true. When there is no actual use case, there is no actual value. But again, the author generalizes. Not everyone is in it to promote some coin. Some of us are just looking for a technical solution.
Let's take a second to remember what happened with e-gold and liberty reserve. There's a reason why cryptocurrencies are necessary. They aren't backed by anything because they are decentralized. They can't be backed by the obvious (precious metals) because that is highly regulated.
>Those regular currencies provide tremendous value to our societies.
This is as far as I have time to go right now. If you think there's no issue with traditionally issued paper and digital money, then there's very little to say here. The US is about to issue $2 trillion in monetized debt.
From Roman coin clipping to the Wiemar republic's hyperinflation, if you can't see what is happening and actually believe that this process is 'adding value' to society...
If hamburgers were once 5 cents each, how has value been added?