Printing money without adding any new value to an economy just leads to inflation because it reduces the purchasing power of the currency. It's like adding extra money to a board game without increasing the number of properties or resources. It might look like everyone's richer, but prices just go up, and the value of each dollar stays pretty much the same. So, a country can't really print itself into wealth without causing serious economic turbulence.Printing money doesn't create wealth, it can only redistribute existing wealth, leading to higher prices without an increase in productivity or real value. The perceived increased wealth is a nominal illusion due to inflation, not actual economic growth.
A lot of modern currency, specifically fiat currencies like the US dollar, is based on what's called fractional reserves. In very simple terms, the government only has a very small amount of actual money.
Printing more money decreases the value of existing . We call this inflation. So, money printing can make your country poorer. Printing too much money can make you very poor, very quickly. Like the in Weimar Germany....
It has to do with supply and demand. If you print more money, you increase the supply of money. Because supply is up, the value of an individual dollar decreases.
It also isn't a good idea to print money like that for another reason: other countries will lose faith in its value. A lot of countries use the US dollar as their currency. If we print more of our money like that, the value of the dollar will tank. Other countries will stop using the dollar because of its falling value. Thus, the US economy will tank.