I'm still dying on the "18 years is a failure" hill. It's a full 23 years to IOC from program start. What if we needed its capabilities in a peer conflict during years 10-17? We got lucky, no?
And if we haven't needed it yet...
It's fair to point more at the JCIDS process than the acquisition process. Once the requirements are set, success or failure is dictated (or at least the odds are set) by technology and physics. You just have to wait decades and trillions of dollars to find out how it ends.
I did stuff on the USMC EFV amphibious vehicle that was a 35 ton jet ski. The Marines had to have that high speed in order to execute their mission, it was a hard requirement. Until the laws of physics and available technologies intervened and the program failed. Now it's not a requirement.
A supersonic plane that hovered would have been useful in the Vietnam War era too.