if those weapon platform are old cheap and obselet, doesnt that also mean the China is really stupid for wasting billions of dollars on them? mkk are more capable than any other plane in China. Super 10 should be something thats on parr with F-22 or F-35, which means they are going to be expensive and very few deployment. Su-27 and its variants can still have a place in plaaf as a low tech combo to super-10.
that's not really correct. J-10 is far more capable than the mkk. I personally think they needed mkk at the time, because China did not have anything with that kind of multi-role capability. Also, it gave China a lot of ground atttack weapons and PGMs and such. Which, they did not have before. But, it seems like China's ground attack munitions are really rounding out recently and JH-7A can make good use of a wide variety of Russian and Chinese weapons, so that's why you are not really seeing any further purchase of mkk (along with the fact that mkk aren't that great of air superiority platform).
As for flanker's place in PLAAF, I've been pretty consistent on this.
As for some of the stuff we got from the Russians, I wouldn't call them top of the line even if they are top of the line for Russians.
The kilos are from the 70s and they certainly aren't as quiet as modern designs. Sovs are also from the 70s and certainly don't measure up to the new AAW ships in Europe and East Asia (referring to KDX-3 and Atago). The list goes on.