Wait. You mean a country that takes education seriously and doesn't kowtow to religious nonsense is better at science than a country where "evolution is just a theory" appears in high school textbooks?
Who could have guessed?
(Before you jump on me, this is not an endorsement of the Chinese government, or even their education system; it's just an acknowledgement of one aspect of the two nations education systems).
China may not have religious nonsense in textbooks post-genocide Cultural Revolution, but it does have superstitious nonsense so your distinction isn't really valuable.
The real reason is that China has a huge population 4x that of the US, and like you already mentioned has a strong culture of valuing education because like in most recently (or currently) impoverished nations education is often the best way to improve your conditions. The US doesn't really have this problem, college graduates make more money but the alternative isn't living in abject poverty or even starving; most highschool graduates do just fine.
"It's just an acknowledgement of one aspect of the two nations education systems"
How does one acknowledge a distinction that doesn't exist in reality?
China may not have religious nonsense in textbooks post-genocide Cultural Revolution, but it does have superstitious nonsense so your distinction isn't really valuable.
China has superstitious nonsense in it's textbooks? Such as what?
One factor might be that persecution of Chinese-Americans has led to many prominent scientists returning from the US to China in recent years. Their new output would contain and be domestic citations.