If they didn't vet, people wouldn't use the service. And the government demonstrably does not do a better job of vetting than private individuals. Some example

If they didn't vet, people wouldn't use the service. And the government demonstrably does not do a better job of vetting than private individuals. Some examples: has lower quality employees, it makes it impossible to "discriminate" on many different dimensions, and it certainly does not have a Canada-styled skilled immigration policy.