I've never understood the argument that people would want to suppress the (accidental) lab-leak hypothesis out of a desire to protect the image of China. If the lab-leak hypothesis is incorrect, that doesn't change the fact that the virus originated in that country, it just means that the virus emerged from a wet market.
I'm not Chinese, but I'd imagine that a country's image is more harmed by accusations of having backwards cultural and food habits (and insufficient government regulation of dangerous markets) rather than potentially just one lone scientist making a mistake while working on advanced genetic research, which is a risk at any such lab in the world.