I don't think the $750B/yr is the problem
for why the US doesn't fare well in simulations against first tier opponents.
I think that is is a matter that wars are hard to win, our victories against Panama and Saddam's Shiite cannon fodder notwithstanding.
Particularly wars that aren't fought on your own turf.
For every expensive combat and control system you develop, somebody is at work figuring out a way to defeat it- often with cheap and simple methods (think IEDs).
As they note here, the F-35 does appear to currently be the world's premier fighter, in the air. Unfortunately it has to land.
Anti-ship missiles force aircraft carriers to stay far offshore.
The good news is that any of the potential opponents also know that a victory over the US is far from certain and that they'd take an enormous amount of punishment in the process.
Having a strong military deterrence is a good thing at them moment but winning is a lot more about soft power and diplomatic maneuvering.