The U.S.'s immigration policies also take a highly biased sample of Asian immigrants, generally the highly educated, and those who already have enough money to do things like pay out of pocket for a U.S. masters degree (which gets you a student visa, which makes it easier, though still tricky, to end up with other kinds of visas). Geography alone gives us different socio-economic cross-sections of Asian versus Mexican immigrants, for example.

In cases where that isn't true, Asian immigrants aren't generally any more successful than other immigrants. For example, the Hmong population in the U.S., who mainly came as refugees from the Southeast Asian wars, has a very high poverty rate even 35 years later (around 30%, versus a U.S. national average of 10%).