It doesn’t have any air-to-air weapons. What’s it supposed to fight?
It’s not classified as a fighter, aside from the “F” in the designation. It’s a ground attack aircraft. According to wikipedia it has not been unusual for the US Air Force to use the F designator for attack aircraft in the past. Also:
Snap
It’s an “F” instead of an “A” because it’s small, pointy, and fast.
If you read that Wiki article an even bigger puzzle is why the designation number 117 was kept. The US military switched to the unified numbering system in the 60s (that’s why Vietnam & earlier planes ran into the 100s but in the 70s they all got reset i.e. the B-1 & B-2 and the F-14, 15, 16 etc.) The plane was expected to be given the ‘F’ designation for the reasons stated above, but F-19 not 117. A lot of theories exists, disinformation being a popular one.