by far the weakest arguments in favor of immigration are the ones that focus on "labor shortage"
like, believe it or not immigration is actually good because it's generally preferable for people to have freedom of movement (and generally preferable to avoid wasting resources on restricting freedom of movement when those resources could be better spent elsewhere) not because business owners can benefit from exploiting immigrant labor-which does not help immigrants (who believe it or not also want to be paid a living wage) and does not help domestic born workers.
and frankly, when people make critiques of immigration that focus on how it might affect wages and employment, you should be countering that by offering methods to protect wages and employment that are more effective than anti-immigration policy (for example job guarantees, minimum wage, better labor protection overall, etc) not dismissing those concerns as unimportant or, worse, framing low-paid labor as some kind of benefit.
if you do the latter, you've made it clear that you don't actually care about the well-being of immigrants.