u know, this makes u think a little.
how the hell are countries like china with very little experience with airplanes fielding 5th generation prototypes already? maybe they arent 5th generation after all.
the JSF is extremely complex and this has been proven by all of the delays, but people say j-20 is more advanced...why is that? imho i believe that the j-20 is not true 5th generation it may have stealth but its software, electronics, engine, and other systems probably are not 5th generation it takes a LOT of time and money to refine a plane to be true 5th generation and that's not done overnight even if you reverse engineer. not to mention the complex supply chain you need (in the j-20s case im sure a few parts from other aircraft were used to save costs)