East Asians and South Asians have fared well in America, with ample selection bias in the population due to highly skilled immigration, but not so Southeast Asians and Pacific Islanders, who have drastically lower economic and educational attainment.
The uncomfortable state of being Asian in tech
Tracy Chou

This statement in turn expands the confusion. Where is this statement based? East Asians, South Asians, Southeast Asians and Pacific Islanders themselves are not homogenous. Figure 3 of https://www.census.gov/prod/2013pubs/acsbr11-17.pdf shows that Koreans and Chinese have higher poverty rates than average Asian Americans. Doesn’t sound like East Asians fare drastically well economically. Table 10 on http://www.cis.org/sites/cis.org/files/articles/2012/immigrants-in-the-united-states-2012.pdf also contradicts this. See East Asia vs Asians data on poverty rate.

There are data for education as well but I believe it is the responsibility of the author to verify these claims.