Russia gave (ie sold) everything to China that China has.
Ukraine sold them their first aircraft carrier. The ones they built look like it.
We reported on all this here 25 years ago.
The J20 (much like the Su-57) are nowhere as stealthy as the F-22.
The Su-57 has an RCS between 0.1m² and 1m² with fair assessments being about 0.5m²
The J20 has an RCS that’s been reported to be 1 to 3 square meters, with one report from Taiwan of upto 20 square meters. Expert assessments place it at between .08m² and .3m² which are still magnitudes larger than the F22 and F35.
The F22 is .001m² or less.
For comparison a bird is .01, a B1 bomber is .75m², and an insect is .00001
Billary to the rescue
It is not just about building the jet engines. It is about building jet engines to fly in polluted Chinese airspace.
China predicted that Russia wouldn’t service or provide engines and components for up to 40% of China’s fighters.
Taiwan should invade China : )
Why? Because they have not yet stolen the tech to make the tools to make crystalline turbine blades, but keep in mind that until last year, China could not make the ball of a ballpoint pen.
The rest of it is gobbledygook.
Zhou Xibedn will get them up to speed as long as he gets his cut.