The range a stealth jet is visible on radar is proportional to the RCS. Which is why stealth jets use standoff munitions.
It's not just the west. China is likely on par. Russia was near par in terms of defense but it's now been attrited.
China isn’t on par, especially when it comes to doctrine you don’t develop that in a simulator.
RCS: Radar cross-section.
<https://en.wikipedia.org/wiki/Radar_cross_section>