The biggest challenge, to this day, is the language barrier.
And in the case I mentioned, productivity was fairly equal.
The whole idea of the H-1B is that the company who wants to use this visa program CANNOT find any Americans/locals to do the job or have the minimum qualifications to do the job.
Whether foreign national Indians are better workers or work harder, etc., is not the criteria for H-1B. It is that Americans can NOT be found to do the work.
ANYTHING else is a lie. It is perjury on a government form.
It is correctly a high-standard to meet. Over the years, it has become a joke.