Then the employers are breaking existing laws! H1-B visa application by an employer requires them to show there is a shortage of US citizens with those skills. Prosecute the EMPLOYERS!
On the other hand chain migration is a 100 times bigger problem in terms of welfare handed out to them. I have relatives who came her as chain migrants, and since they were over age 65, are receiving social security checks for life. And receiving gov’t paid healthcare. And food stamps. And other benefits!
At least H1-B visa people have jobs and pay taxes. And it is a temporary visa. Chain immigrants are PERMANENT.