If they didn't burn old money we still be in the deficit?
If you stopped trolling would you still be a troll?
The money which is burned is money too damaged to be in circulation anymore.
The more of it is out there the less it is worth.
Then the cost of the US dollar would decrease. This happened during the Great Depression. There are stories that people would go to a store with wheelbarrows full of money. The store owner would take the wheelbarrow and leave the money.