This is classic “Social Credit” economics. Money is just numbers, debt is a fiction created by accountants and the government can just print as much money as it needs to pay off the Government debt. If you tried to run a household like this you would soon be bankrupt or in prison.
Printing off more currency devalues the currency to the degree that you print or issue more electronically: if you double the money supply, the money that already existed is now half the value it was before, all things being equal. Of course such an action would make international trade abandon the US Dollar as a reserve currency in favour of a more stable currency -the Yuan or the Euro. That would make the US dollar drop far further than the “Quantitative Easing” itself would imply.
It is inflationary in the extreme, so can only be used to stimulate the economy in times of low inflation. It is not the perpetual motion machine that its proponents think it is. The Government issuing more currency is not the cure for structural problems in the economy, but it is popular with left wing economists because it devalues wealth, while simultaneously discounts debt.