Because it is currency itself that you measure everything else against. What my sentence meant is that without transaction fees it would be a zero sum game -- ie if you undid all crypto-money transactions then nothing is left -- but with transaction fees their sum is a negative number. But you need to measure this in something.

Note how stocks are decidedly not like this because if you undid all stock-money transactions the sum would be positive because of buybacks and dividends.

> Because it is currency itself that you measure everything else against.

So what? I cannot see the significance of that. There are many possible measures of value.

> if you undid all transactions then nothing is left -- but with transaction fees their sum is a negative number. But you need to measure this in something.

Yes? So what's the important difference between cryptocurrencies and traditional currencies?

The thing is you can buy anything in this world for money. That's what money is for. Thus, we measure these things in money.

I don’t see how it answers those questions.