Why taxes?

[foolsguinea]

If we eliminate Bob the Civil Servant's position, then we're not compensating whatever volunteer spends his time doing the job for free. And time is money, so we just taxed that volunteer for the job instead of spreading the cost around society.

The opportunity cost of relying on unpaid workers is entirely on those civic-minded volunteers. But if we use the state to accomplish the same ends with civil servants, we spread the cost around.