There are different groups in China. The bulk of the people will never travel internationally. They don't have much money/influence in the country. The ones that visit Canada are the rich and powerful. They are the leaders. They are the ones that will go home and set CCP policy. They visit Canada and see clean water and reasonable living standards are possible. When they go home they will demand those things. They will demand change when their college-age kids studying in Canada don't want to come home, or don't stay long when they do. That sort of slow influence can be more effective than the threat of violence.