They are not the most educated, American jobs for Americans first.
As for assimilated tell that to the dead family for one of the “assimilated” truck drivers. Ya he was not H1B but puts the lie to the idea of assimilation.
On average, Indians in the US are significantly more educated and make significantly more money than other ethnic groups.
https://www.pewresearch.org/chart/educational-attainment-of-indian-population-in-the-u-s-2019/
The H1B Indians are some of the lowest IQ individuals out there compared to the Americans whose jobs they stole.