Why do US twin seaters replaced the 2nd pilot with RIO/WSO after F-4E/F-111?

In War Thunder, the last US fighter jet to have 2 pilots is the F-4E and F-111F. F-4J/F-4S had that pilot replaced with a RIO.

I wonder why would the Navy do that, and why would this trend continue on into other US/Israeli aircrafts like the F-14, F-15E and F-16D?

Edit: I had seen articles saying F-15E/F-16D should have the WSO also be able to control the plane. Is this an error in War Thunder?