"Then in the late 70s/80s they went all twin jet for some reason"
Single engine jets are smaller and lighter. USN started to use dual engine planes since the FH Phantom and the Banshee, but smaller carrier couldn't operate with larger, powerful aircrafts like the Phantom II or the Tomcat - which being designed for a large payload and great operational range were inevitably larger and required more power and survivability.
The Midway class was the smallest carrier that could operate the Phantom II, while the Tomcat required the larger Forrestal and later designs.
Biting the hand that feeds IT
