The F-35 is a nightmare. The F-15 is proven. A bird or a BB brings down an F-35. F-15 a little more robust in the aerodynamic/electro-mechanical dimension, not to mention 2 engines, enough to bring it home after one is gone. F-15 even landed with one wing gone. F-35 just went “a bridge too far” down the McNamara road of hoping to get one weapon do to the job of several others. I think the F-111 ended up being called the Ardvark. I wonder what name the F-35 will end up with? The Matrix? Just too much overly optimistic engineering crammed into a flying machine. Well, that is my impression.
No new aircraft designs were needed after the F-4.
[The F-35 is a nightmare.]