How much effort do credit-rating, fraud etc agencies make? A centralized currency requires trust, which crypto-currencies don't. To compare value, you need to add a price tag to this liability. The lower cost comes from the savings made in not having to secure against the central authority itself.

There are other upsides like independence.

It’s more efficient for everyone to take a bus and never drive a car alone. But cars give freedom. It’s more efficient for the world to eat soy lent instead of a diverse diet.

Complaining about how cars use more fuel than buses or how strawberries take more water and fertilizer than soy neglects to capture all the benefits gained for those higher costs.