Aircraft works for the US because they have the infrastructure: bases, aircraft carriers, tankers, etc. and they are always planning to fight against weak enemies like Libya, Syria, Iraq, Afghanistan, with no air defense systems. Survivability is not a main concern for the US, reusability is.
Aircraft doesn't work for China, because China doesn't have the infrastructure, ie bases, carriers, tankers etc. Or very limited amount of infrastructure compared to the US. Lastly, China is worried about confrontation with strong nations like the US or Japan etc. which have very advanced air-defence systems and air-superiority fighters. So unlike the US, survivability is extremely important for China, more so than resuability. Thats why ballistic missiles are more suited for China's purposes and aircraft less so.
Different countries, different needs, different strategies. So I agree with the assertion that China will not go crazy and build hundreds of J-20s, because it doesnt fit in their doctrine.
I mean, you're purportedly an Indian so I'd think you're ignorant about the basic situation.
The basic problem between air attack and air defense is that air attack can be highly concentrated on a specific location. Surface-based air defense, on the other hand, ends up being dispersed, and because it's relatively immobile, it's more vulnerable to bombardment by means other than air attack, including cruise and ballistic missiles.
Just to offset the planned 2500 F-35s the US is planning to build, including the 1200 F-35s that will likely be in the Asia Pacific Region, will require hundreds of J-20s just to conduct air defense.
Why? Because you'd need to blanket the entire Chinese coast in air defense systems to have the detection, tracking, and destruction capability vs mass stealth attack such as the F-35 or, for that matter, the B-2 or B-21 systems. The better way to do so would be to employ counter-stealth AEW&C, which are mobile, and stealth fighters, which are also mobile for this task. Long-range anti-stealth radar, likewise, can provide detection and tracking to cue the mobile air defense elements.
You also have to remember, the longest ranged air defense missile (S-400) reaches out 400 km, and with all anti-air missiles, you have to wonder what the effective range is against a maneuvering target. A long-ranged cruise missile, such as those in both Chinese and American possession, can range out to 800 km.
And I'll also point out another issue. China isn't the United States, which has global interests with global warfare capabilities. China is China, whose immediate military interests amount primarily to Taiwan, and then the Sino-Indian frontier on a much reduced scale. China only needs to be able to put air power into its adjacent regions, so China doesn't need the exhaustive tanker and carrier infrastructure the US has. Bases on Chinese territory are enough.