The Valkyrie was also doomed by the fact that even a Mach 3 bomber couldn’t evade being tracked and shot at with emerging SAM systems. It was beautiful though and it’s a shame that the B-1B was really never “finished”. It still doesn’t generate enough power to run all of its systems concurrently and we signed a terrible treaty preventing the use of its hard points. The A-12 loss really hurt the Navy but not as much as the premature retiring of the a-6 and s-3 which both should have probably been given an extension program and modernization. The super hornet has evolved to be the best fourth gen fighter on the planet though (opinion based on its high proficiency in every task it is assigned). The carriers.. the SCS ship will finally be realized because technology has matured the F-35 will finally enable amphibious carriers to have proper legs and teeth in its strike role.