Also true when your own fire control system is trying to get a lock on its target before you even fire. And getting though jamming and spoofing takes more than an 8 bit computer with 4k of memory.
While it is true that in terms of basic performance we hit a plateau with the Century series of fighters, but today’s aircraft have much more sophisticated avionics and much more efficient engines for longer loiter times and higher dash speeds without afterburner than an F-4.
The limiting factor in the F-35 today is software development.