I get it why it's useful in practice here, but on a conceptual level relying on proof-of-work always seems weird to me. It's like saying "you have to pay to use

I get it why it's useful in practice here, but on a conceptual level relying on proof-of-work always seems weird to me. It's like saying "you have to pay to use this service, but instead of giving the money to the host, you need to drop it down the drain". From an economic standpoint it just doesn't make any sense.