You're right, if we want to eat real Chinese food we have to go to China. Chinese, Vietnamese, Indian food served at restaurants all over the world are only inspired by those cuisines. I realized that when I moved to Poland from Vietnam. Food served at "so called" Vietnamese restaurants has nothing in common with food from my home. Of course we can find some places, run by the asians who try to bring their real national cuisine to wider audience but still those places are in the minority