Somebody came up with a budget to make a 4 in 1 plane, assuming it would cost less then 4 different planes. Well, it appears the cost of the 4 in 1 plane cost more than anticipated, to the tune of $163bn. There’s no evidence 4 separate/less complex designs would cost more than the F35.
But, the real point is this. Why do the USA need the F35, it’s not as though they have ever failed to gain air superiority with their present fighters.
Why does Isreal need F35’s, sureley their previous planes where quite capable of attacking Palastinian/Lebanese civilians or Iranian drones.