Using one multi-purpose aircraft has some fantastic advantages if you can pull it off.

A carrier can use all its combat aircraft to fight enemy aircraft (effectively double the number of anti-air aircraft on board), then after the enemy Air Force is the destroyed, switch around to using all the F-18's to attack ground targets.

With specialized aircraft types, some combat losses focused in a particular role can cripple the entire air wing, whereas with multi-role aircraft, you can keep right on operating.

It's great from a maintenance, logistics, and training as well.

The Air Force doesn't, but the Navy does.

The thing that everybody leaves out about the F35 is that you can take a relatively small ship, put a half-dozen F35's on it with some drones, and you have a tiny carrier with a remarkable amount of firepower.

So, now you don't have to sail your gigantic ass Nimitz carrier into the forward theater where a lucky cruise missile hit can cripple your entire fleet capability.