The problem can be that the net whole is “better off” by some minuscule amount but certain subgroups are disastrously worse off.

For example, factory jobs disappearing usually increases the nations GDP “as a whole” but has disastrous effects on the poor communities that provided the labor.

Or another way to put it - if immigration is a net benefit and has little downsides, then a minimum wage for immigrants (legal or otherwise) of $45/hr should be fine.

(Even that might not move the needle much as immigrant labor, both legal and illegal, has “corporate” advantages that can’t be matched by residents. Being able to skirt regulations and laws because you know your employees can’t complain without risking their residency is a powerful tool. See: H1B abuse and OSHA abuse.)