Well the Chinese defector and former Party school professor Cai Xia also said that the PLA is incapable of waging wars because corruption really diminished its capabilities and weapon qualities.
In the West, it is really easy for folks to believe these ideas. Honestly, I think both sides are correct to a certain extend. Yes, both Russia and China have structural corruption issues that could erode their militaries' fighting capabilities. Yet, as with the case of CCP, I dare to hypothesize that the way corruption erodes fighting capabilities may be far less severe than those in the Russian Army, at least with Xi in charge. If there is one branch of the Chinese government that Xi had made more competent, it is the PLA. When I was much younger (before 2012), PLA officers' vehicles (mostly Toyota, Lexus, Audi, Volkswagen, or Mitsubishi jeeps) could part in any No-Parking spots in Guangzhou. If they run over pedestrians, traffic cops didn't even dare to touch them, because military officers could get away from punching police officers or other folks in the face in public. But now, military and police vehicles are the ONLY ones stopping before pedestrian crossings. Officers are usually not allowed to walk around the city in uniforms or drove their military-plated vehicles, but if they do, they would usually be super respectful toward strangers (at least far more respectful than other civil servants responsible for stamping licenses).
In general, I have my own reservations about Xi's crackdowns on free speech and the education industry, but when it comes to making the PLA more disciplined and competent, Xi has done a marvelous job. Well at least China is a military power to be reckoned with because of Xi. He deserves credit for making the country more secure (think the massive nuclear, ICBM silo, and naval expansions), the PLA more trusted by the people, while deterring domestic (Xinjiang) and foreign adversaries (an unnamable superpower and its puppet government on an unnamable island waiting to be suffer the same fait as Ukraine).