Yes, this is indeed what a typical staffing company does -- except citizens at staffing companies can jump ship anytime when a better opportunity comes their wa

Yes, this is indeed what a typical staffing company does -- except citizens at staffing companies can jump ship anytime when a better opportunity comes their way. H1Bs, while not shackled, have a lot of tethers to their current employer which makes switching very difficult. Their lightly-tied handcuffs also make it very difficult to find better jobs/salaries/negotiate and result in holding wages down.