Part of the problem is that the F-35 was pitched as saving money by doing everything for everyone. It was going to be a lightweight fighter with carrier-landing durability (contradictory) that had options for both single-engine, multi-engine, and VTOL engine (all contradictory), with a big-wing and small-wing version, that could be a quasi-air-superiority, quasi-guided-missile, quasi-bomb-truck, or even wild-weasel/SEAD (all contradictory roles), and replace about 75% of the aircraft in the arsenal.

The SR-71 was designed to do one thing. Go fast and take pictures. It didn't carry bombs. They eventually tried to put a drone on it and it didn't work and was abandoned.

You don't even have to look back as far as the SR-71 though, the F-22 was a reasonably successful program - bumpy, expensive, but it produced what is the world's preeminent air-superiority fighter. It is not a bomb truck, it does not land on carriers. It does one thing well.

Others are not wrong about the fact that the F-35's merit to Congress was as a jobs program, either. This is in fact what a lot of military spending really is. We build tanks only to drive them into the desert and store them, all to keep those production lines running and keep people employed. They could be building trains or something else equally well.

The underlying problem there is that the US political system has become byzantine and cumbersome. When "played" adversarially with all "players" using the maximum extent of their political powers, it takes supermajority control of all three branches of government to govern. This has promoted a byzantine system on top of that to try and come up with mechanisms to fix a broken, unfair, and non-representative process. Massive over-spending on military as opposed to other types of government-sponsored research, production, etc are only one side effect of that.