I have travelled a little in Japan, but never China. I enjoyed a number of things, from home cooked to banquet food to 7-11 to small restaurant. Much was good but, personally my taste buds got tired. However, if I lived in Japan, I would miss Chinese food, I think, at least Los Angeles style Chinese food. If I ate Chinese food daily, I don’t think I’d miss Japanese that much. I wasn’t that excited about cold vegetables for breakfast, for example.
There’s a big difference between Chinese food in the U.S., and Chinese food in China.
While there is some really great food in China, much of it is just meh.
One major difference between China and Japan is that I’ve never had any issues eating anywhere in Japan. Heck, even 7-Eleven in Japan has some pretty good food. I’ve eaten at numerous roadside and streetside food vendors in Japan, where there just seems to be a higher level of pride associated with whatever they are serving. Perhaps the term, ‘ikigai’ would be somewhat appropriate.