In the Pacific, efficiency is the main goal for fighter jet engines. The goal of the WS-15 is to have F-35 level efficiency while being able to go relatively far in the supersonic regime and outrange every US plane.

And of course the engines for strategic lift planes are based around efficiency first.

I could believe the J-20 could match the F-35, and apparently the Air Force could believe it too because there’s also the F-22. And strategic lift planes use normal jet engines not supersonic ones so they face the same issue as Chinese airliners do.

The F-22's engine are not as good as the F-35 engine. It gets around that by simply being a larger plane and having a second engine.

Both modern fighter jets and airliners use turbofan engines, the difference is the bypass ratio (hence the size of the bypass blades). For both low and high bypass, Chinese engines are supposedly better than Russian engines. They aren't better than Western engines but they're not that far apart. As far as airliners, the airliner engine is a different design from the WS-20 because of different requirements. It started development far later than the WS-20 and it has been flight tested after only 5 years, which isn't bad at all.