As a Chinese, I can name couple reasons why we would not produce any world class player at least in the next decade:
1. Small football population. with total population of over 1.4B , the registered players with FA was less than 750K in 2019, that means less than 0.1% of population participate in the system and play regular games and tournaments arranged by FA, not mentioning at the professional level.
2. Football is a luxury sport in China. You barely find any free park or playground that you can play football on , unless you can rent a field by hour. Of course, you can't play on streets as well. School fields are always over-crowded.
3. Malfunction of football academy & career system. If you would like to develop a professional career, you would have to afford the kits , high-protein diets, the tuition fees and all other misc. costs in professional PE schools, and sometime bribery to get picked in the selection, until you can barely make a living after becoming a professional footballer. If you did not have the talent to make it, you are doomed, as alternative career related to football basically non-exist: jobs like coach, scout, pundit are underpaid and you can't take them as full time job to survive. So you can imagine such high-investment, high-risk career path is not popular in China and do not attract talent to stay with it.
4. High carb diets. Set aside race in the discussion, Chinese diets are high carb and low protein, so basically it means if you stick to Chinese diets in your early age before even practicing football, you can't really grow as strong as kids in other countries.