I'm an "old fart" who feels that the British aircraft industry was fatally damaged by not only Government, but by the various bodies charged with "development" actually causing the exact opposite.
I still feel that the Comet, which due to the square windows was flawed, took too long to redesign and allowed the Americans (who we'd given the green light for transport aircraft development) to come up with the 707. We were still producing beautiful looking but totally unsuitable aircraft such as the Brabazon and could have competed fairly with Viscount and developments (not necessarily Vanguard) Britannia Trident and VC10.
I'm not au fait with why some say it was an economic disaster, but overlong development times meant that the conditions an aircraft was designed for no longer applied by the time it entered service.
And I guess that takes us back to the OP question - aircraft foisted when the requirement no longer existed.
But isn't that what the military always complain of, being given equipment designed to win the PREVIOUS War, not the CURRENT one?