The groups which you mention, most of those Indians, Chinese and others who come to US go through a filtering process in terms of student or work visa. So you get educated, successful and highly motivated people who also have higher incomes compared to the average income in their native countries.
The US is is literally getting "good" immigrants from those countries. You are not getting the poor unmotivated individuals.
These motivated individuals will pass on those characteristics and their wealth to their kids.
The current African American's ancestors had no such filtering process, combine that with systematic racism and poverty its not too hard to imagine why they fall behind.