You are living in a fantasy land world. My good friend lived in China for five years. Needless to say, he doesn’t speak highly of their ethics, politics, and human policies. I temporally lived in S. Korea for a few months and there were solid blocks of days the air quality was so bad you could barely be outside. Of course the pollution made its way down from China’s unregulated factories. I quickly realized South Koreans are frankly quite racist against the Chinese.
It’s not just Koreans. Nearly all countries near China hate Chinese (probably except North Korea). The air pollution has been definitely the reason why it got worse but largely it’s been historical reasons