When I got hold of my first fighter, it was considered to be the most dangerous aircraft to go against ever built. 23 years later, that same aircraft is still the most dangerous, (although the F-22 is promising) though soon to be phased out of service. If in 23 years, the Services have yet to build an weapon that can defeat the Tomcat/Phoenix, I doubt fighter pilots have anything to worry about for the next 30-35 years, when the next generation fighters are retired.
Harrier or F-4 (which I once saw go to pieces during a video on PIO)?
Yeah, that's what Gary Kasparov said. What he forgot is that computers double their capabilities every 18 months.
There's no reason why the robot-piloted plane itself needs to be any more expensive, less mechanically sound, or worse in communication than any human-piloted aircraft; the worst-case scenario is that you simply replace the pilots of existing aircraft. But that's already a winner: computers are capable of executing much higher-g turns than humans. Also, they're much better at taking calculated risks, because they know to several decimal places how much leeway they have...and they are only as risk-averse as they're told to be.
What I expect, though, is that the "fighter planes" of the future will essentially be intelligent missiles. Extremely intelligent missiles.