I agree that freedom, opportunity, and security are attractive enough incentives.
If they want to come here and be Americans, without us picking up the tab, that is one thing, but then they come here and live in enclaves with little enough culturally different, often on our dime.
So cut them off. No more publicly funded welfare for non-citizens (for starters). Charities who chose to shell out can do so with private money.
If there is no need for fiscal incentives other than the opportunity to come here and be a success, why present them?
That isn’t going to happen and everyday that legal immigration continues, the less likely it becomes.
We need to just end importing millions of people to this already crowded nation.