How fast do brake pads wear out?

I’ve long suspected Maryland’s car inspection system is inherently corrupt.
After all the same guy who inspects your car (for a fee) can repair it.
I’ve dealt with this system a number of times and I’ve never seen a used car pass without an additional vig (loan shark term for exorbitant interest payment).

The upside is you only have to go through this once for as long as you own the car in MD.