I touched on it upthread and the wiki very briefly mentions it, but politics killed the F-20. It essentially ended up being a direct competitor to the F-16 whic

I touched on it upthread and the wiki very briefly mentions it, but politics killed the F-20. It essentially ended up being a direct competitor to the F-16 which the USAF had already selected as its light fighter. The USAF wanted the F-16 to be adopted as widely as possible to help reduce their own operating costs. As a result, friendly nations that had previously been customers for aircraft like the F-20's direct predecessor, the F-5 Freedom Fighter, were being lobbied quite hard by the USAF to adopt the same aircraft. The USAF either didn't promote the F-20 at all or actively downplayed it versus the F-16. It didn't lose because it was inferior. It was a very solid aircraft and, in some ways, actually exceeded the F-16; it was BVR capable from the start while the F-16 didn't gain BVR capability until years later, for example. But the USAF was already all-in on the F-16 and Northrop lost the political game. The Scorpion is targeting a completely different market than anything the USAF really has a vested interest in currently other than the Air Force being hostile on spending on anything that isn't the JSF. I don't have particularly high hopes for the US adopting it given that, but the market they're going after is different enough that they're not fighting for the same customers like the F-20 did.