Why was the 5 Star Rank Done away with after Omar Bradley died in 1981? Why not have 5 Star Rank brought back since all of this fighting ?

We had 5 stars in WWII to deal with other country officer's (Field Marshall's, Army Commanders, who were equal to or out-ranked our 4 stars.

Because it's not needed. We have enough GOs in the military. We have 42 Active Duty 4 star GOs alone. The Army alone has 200 some odd GOs total.

The 5 star rank is reserved for a major war only. Usually for a very senior commander who commands over several nations military. Ie. WW ll and Korea.

The rank isn't gone, its just not used. The advent of unified commands probably has a lot to do with the disuse of the 5-star rank. The Commanders of the geographically organized unified commands in particular exercise the level of command authority held by previous Army and Navy five-star officers (GEN Eisenhower as Supreme Allied Commander is a great example). Positional authority of unified command commanders places them in charge of service component commanders even when those commanders are also four-star officers. The power of the Services in general has decreased somewhat since the 1986 Goldwater-Nichols Act that changed the relationships among the CJCS, Service Chiefs, and Unified and Specified Command Commanders. Unified Command Commanders have a direct line to the Secretary of Defense independent of the Service of which they are a member. They can and sometimes do recommend courses of action within their areas of responsibility that are different from or at odds with the recommendations of their Service Chief or Service Secretary. Additionally, some Unified Command Commanders continue their career as Chairman or Vice Chairman of the Joint Chiefs of Staff, both of which are currently four-star positions.

Reintroduction of the five-star rank for any position other than CJCS, who is by law the most senior military officer, could precipitate proliferation of five-star officers. For example, if the Commander of Central Command was designated a five-star position, then the CJCS would probably be also designated a five-star position. Additionally, the other unified command commanders would start to present the case for their position to be elevated to five-stars, some or all might be. Doubtlessly, the Service Chiefs, with the possible exception of the Space Force, which is part of the Department of the Air Force and pretty small, would advocate for their elevation to five-star rank. We'd end up with a dozen or so five-star generals doing the same job as the current four-star generals were previously.

Shouldn’t their be a 5 Star directing the 4 Stars?

I would venture to say that we haven't needed to have a General of the Armed Forces since we haven't been in a fully declared war since WWII.