The J-7 is pretty odd.
IIRC, it's basically based on a modernized Russian MiG design that was upgraded, and it had numerous advanced technologies built-in to it from the ground up; however, a lot of those technologies were either stolen (mostly from the United States via espionage) so they don't truly understand them (they're more replicating than developing what data/examples they have, I think?), or they are all just immature for their [China's] technological development level, so the implementations go... awry, to say the least.
And for all the hype of the J-7, it's pretty much a new last generation fighter on par with the (failed) Eurofighter Typhoon.
So, yeah; not really a threat when you have better, more upgraded last generation fighters zipping around as its contemporaries, as well as the F-35.