Why settle for a one-size-fits-all model when you can have the best of all situations. If a future F-16 or F-20 prototype can dogfight better than a F-35, then build that prototype. Just don't replace your entire air fleet with it. Likewise, if a future F-15 prototype is better at tactical bombing at night than the F-35, then build that prototype. Just don't replace your entire fleet with that one aircraft.
It's the one-size-fits-all concept of the F-35 that is a stupid idea. It would be like the US building only one type fighter aircraft in WWII and using that one plane for all missions. So which one do you choose? The P-38? The Grumman Hellcat? The F-4 Corsair?
Of course Congress will choose the aircraft that dumps more money into their districts and ensures their re-elections. Which is why the 50-year-old F-16 is still in production.