Economists, big coins, and the theory of money

I'm just thinking out loud here, so don't shoot me anyone who has studied economics and thinks I don't know what I'm talking about:   it seems to me a serious problem for the field of economic theory if economists cannot agree on the effects of something as big as the Trillion Dollar Coin gambit if it were actually used in the USA. 

Here's a Washington Post article about it, explaining some points succinctly:

What’s the downside to the $1 trillion coin?

Experts are not entirely sure, mostly because the idea is entirely theoretical.

A major concern for economists is hyperinflation. Minting the $1 trillion coin would be like creating money out of thin air. When all that new money poofs into existence, the other currency in circulation becomes less valuable. That could hurt consumers, who are already dealing with price inflation.

Then there’s the question of what a $1 trillion coin would mean for U.S. monetary and fiscal policy. Monetary policy means making decisions about the money in the economy. That’s mostly left up to the Federal Reserve, which is somewhat insulated from political tinkering. Fiscal policy means making decisions about what the government spends money on. That’s an entirely political process left up to Congress and the president.

The $1 trillion coin would completely mix the two. It would have the president use monetary policy (creating new money) to solve a fiscal problem (the government is running out of borrowing capacity). Treasury Secretary Janet L. Yellen said Tuesday that such a move “compromises the independence of the Fed.”....

“This is equivalent — the platinum coin is equivalent to asking the Federal Reserve to print money to cover deficits that Congress is unwilling to cover by issuing debt. It compromises the independence of the Fed, conflating monetary and fiscal policy,” she said. “And instead of showing that Congress and the administration can be trusted to pay the country’s bills, it really does the opposite.”

On the inflation side, we get these competing views:

 And this end one might have a point:

Is that at the heart of this, really?   That economics still has no good theory of what creates money and how it "works"?   I had a post about an article that argued this in 2019 - but I think Noah Smith, whose opinion seems pretty well informed, was not impressed.