Tax money from the Federal Budget
I think you may find that the money comes from an excise tax on aviation.
It is a huge pot and the Federal Gummint would really like to get their mits on it for other uses but are not allowed to.
A breakdown
here.
In EASA land they just "nickel and dime you to death".
The FAA AATF is forecast at 16.3 billion for FY 2019.