The agreement reached in Key West gave the Army’s “tactical air support” mission — the mission of flying air strikes in direct support of troops on the ground — to the Air Force. And that decision has had pretty far-reaching consequences.
The first consequence was that the Army has consistently complained ever since that it doesn’t get the quality of tactical air support that it should. The Air Force, they complain, is full of wanna-be fighter jocks who spend all their time and money on sexy new fighters to shoot down enemy planes, paying less attention to the comparatively less romantic mission of dropping bombs on bad guys on the ground.
There is some merit to this complaint. The most effective air support plane ever developed is the A-10 Thunderbolt II, a slow, ugly beast built around an enormous cannon. It is a nightmarishly powerful killer of ground forces, especially vehicles. But it can’t dogfight enemy planes — it’s designed to fly low and slow, not high and fast — so the Air Force brass has never really taken it into their hearts; they’ve mostly retired the A-10 to the Air National Guard these days, which tells you the priority they give the ground-support mission.
The most effective air support plane ever developed is the A-10 Thunderbolt II,
If you included the caveat "in a low threat environment" you could attempt to make that argument.