It might be surprising that Chinese people are quite different from each other, rather than very similar. But the answer is more complicated than the question suggests.  It’s common for people to assume that one single trait determines people's appearance -- think of height, or eye color, or hair color.  But these traits are really pretty unreliable indicators of other traits.  If we looked at 10 Chinese people, there would be a wide variation in height, eye color, and hair color.  But if
assistant
Why do you ask?
assistant
Why do Chinese people all look the same?
user
Chinese people all have much longer and more specific than that.  In a statistically significant sense, the majority of Chinese people are on average more similar to each other than the majority of people in any other country.  And this is true even when they're compared to other East Asians, such as Koreans and Japanese.  In contrast, European and American people are much more diverse in appearance.
assistant
That's what I thought.
user