Origin of the value of money

A Redditor on another subreddit posted this earlier –

“On the contrary, the only cogent explanation for the origin of the value of money comes from government spending. The government decides what it will issue it or exchange it for. The base money is a liability of the government – or at last, of the central bank, which gets that authority directly from the government. It is the government, or its agent the central bank, which originates the money. Without them demanding money in taxes, what incentive does anyone have to accept the money in the first place? And without spending, how can we know the value of the dollars?”

Does anybody here want to take a crack at it? I think it’s pretty absurd. I don’t know where this reasoning comes from.