A non-trivial part of the issue with consulting companies is the long wait for many to turn an H-1B into a green card. If you are going to need many years of continuous employment without ever getting hit by a layoff (which risks a gap in employment), the immigrant might be better of with the consulting company, as they might end up the bench, or just count as employed but not getting any hours.
If the road from H-1B to permanent residency was shorter and more reliable, the advantages of the consulting companies would shrink.
The same as if we didn't end up having to rely on lotteries. Hiring a candidate and hoping for an H-1B is quite annoying if you don't have them on staff in another country, or they are working for you in the US from an F-1. Those consulting companies that have large offices in India can happily submit large amounts of applications of people they already have in India, and be OK with 2/3rds of them not winning said lottery. A smaller company just can't play that numbers' game
If the road from H-1B to permanent residency was shorter and more reliable, the advantages of the consulting companies would shrink.
The same as if we didn't end up having to rely on lotteries. Hiring a candidate and hoping for an H-1B is quite annoying if you don't have them on staff in another country, or they are working for you in the US from an F-1. Those consulting companies that have large offices in India can happily submit large amounts of applications of people they already have in India, and be OK with 2/3rds of them not winning said lottery. A smaller company just can't play that numbers' game