We seem to be confusing literally seeing the enemy with our eyes, and what was the actual capability, which is to DETECT the threat first. When you didn’t have radar, eyes were your only option. Now modern 4/5 generation aircraft have RF (including ESM) EO/IR sensors, and AWACS-Link 16 which allow you to detect adversaries before they can detect you. Stealth assists this by reducing the primary signature of a modern aircraft- its RCS- so that platforms like the F22 can detect and kill first. Whilst having an aircraft like the F35 be all things to all Services is not a good idea, its highly unlikely it will ever be killed because the pilot couldn’t eyeball someone attacking him out of the sun. You say that stealth is a red herring; it seems more likely that insisting a pilot can use his eyes and turn in his seat to see about 10 miles behind him, in the daytime and in good weather, is even more irrelevant.