Indians do a lot better economically than Bangladeshis, black Africans better than black Caribbeans, etc. People from some Eastern European countries do a lot worse than visible minorities. Of the white minorities the Irish were traditionally close to the bottom of the heap historically, but for the last few decades have done well, especially educationally, probably boosted by the quality of Catholic schools (religious schools can receive state funding here and many are therefore free to attend).
Its clearly mostly to do with lack of intergenerational social mobility. Its worth noting that the group doing worst educationally in the UK are white working class boys.
In Sri Lanka which is also my "home" country for a different definition of home the minorities are not "economically lower class" but have faced significant racism and religious discrimination (both sometimes violent) - but have also done the same themselves.
[1] All numbers I know of that compare ethnic groups lump the three biggest native groups into one, "white British".