China didn't ban all the transit boarding for those with low credit, just planes and first class HSR. You can take the normal train, which is still quicker than most countries.
In May, enforcement of China’s social credit system spread to the travel industry, restricting millions of Chinese citizens with low social credit scores from purchasing plane and train tickets.
https://www.brookings.edu/blog/techtank/2018/06/18/chinas-so...