Why do you believe that? What is the basis of that belief?
Are you in the tech business?
Because the companies which hire H-1B visa workers benefit on the bottom line. When companies benefit, they pay more taxes. And they retain core business workers. If your skill is so easily replaceable by a foreign workers, I am afraid you need to acquire better skills and a different profession.
Majority of H-1B visa workers are computer programmers. And that skill is available dirt cheap by the millions in foreign countries. On the other hand there are many engineering jobs go unfilled due to lack of qualified and skilled workers.