The Chinese expect to fight a very different fight and enemies compared to most western air forces, so their requirements are correspondingly different.
For modern western air forces, a big part of the mission profile and emphasis is on bombing hopelessly outclassed enemies even further back onto the stone age. Thus the emphasis on heavy weapons loads so they can dump a lot of ordinance per sortie.
The thing is, at max load, even the best fighter bomber is going to start wallowing like a transport. Not an issue if everything in the sky is friendly and the opponent has no air defence worth mentioning.
China expects to fight opponents who are on par, if not superior technologically. Thus, being able to carry 10-12 or more tones doesn't really appeal if that makes their planes sitting ducks.
The PLAAF is unlikely to be carrying even their 8t full load much if any of the time in combat, so its really a moot point in my view.
Now Wolfie?? lets not let our political ideology get in the way of truth, our Western Air Force is fully prepared to meet ANY other Air Force on the planet, anytime, anyplace, and anywhere. NOBODY wants to meet the F-22 on equal terms, because if you do, you won't be going home to Momma??
The sad fact that we have been engaged in a war on terror, goes back to the US being a victim, of sad little men, who mercilessly killed innocent men, women, and even children?? for example a very fine journalist Daniel Pearl, bombings on an aircraft at Lockerbie Scotland, World Trade Centers, Pentagon et all on 9/11/2001, and I could go on and on??
No, fighters do NOT wallow like transports, and to tell the truth, US transports don't wallow either, they fly very well. Read my post above for the effects of weight on aircraft, affects performance, ability to maneuver, and operating window?? We are sadly off topic, but for what its worth, the J-16 will be able to carry a tremendous load, likely comparable to our own F-15E??? right??