Which ISP do you use? I have friends in Beijing who use Zoom for video meetings (including screen sharing), but they still use regular phone to do the audio part, as they've found audio unreliable. (This is with China Unicom.)
China telecom at home and probably china unicom + china telecom for the office. Audio and video work fine for me, even if it's on the 4g network. Note that my company forked over money for enterprise licenses which maybe the difference here, i think the qos is a lot higher with enterprise license.