Corporations rely on desperate, easily-exploited people in order to make obscene profits. There's no way in hell they'd risk actually cutting off their supply of slaves, or else they might have to drop a couple of percent of profits on paying wages / benefits / etc.
The border laws aren't intended to reduce the number of illegal immigrants, they're there to make those same people more desperate and therefore more profitable, while at the same time stoking the enthusiasm of morons who will continue to vote for more pro-corporate politicians who will shovel even more money to the shareholders.
I'm sympathetic to this idea, but I feel like the cruelty has to be part of a means to an end, perhaps to discipline the labor that does make it through in order to benefit the employing class.
You're looking for meaning where there is none. Fascism does not want to make sense, it very intentionally rejects reason and logic. To fascists, force and power is the only real politics. Few people really grasp how deep the nihilism of it is.
It's simply part of an effort to impose moral beliefs on a world that to them, appears to work without them. Bringing order to chaos. Kind of like the Christian beliefs underpinning such cruelty.
...which is why cruelty is the point. They're getting pleasure out of hurting others. Their pleasure from torment might not be the "true" motivator - I highly doubt the people making these decisions are cackling to themselves like a comic book supervillain while coming up with novel ways of hurting people (though their brainwashed underlings might) - but they get pleasure from power and control, and are willing to pursue it at all cost, which means they do things that are cruel in order to maintain it.
To put it simply, they get pleasure from power and control, which comes at the cost of hurting others. The result is that while cruelty might not literally be the point, cruelty is the end result.
A former friend of mine was heavy into the right wing and worked construction (surprising, I know). He was always complaining about "illegals taking jobs" and how he thought the work they did wasn't good anyway.
One day, I asked him: why doesn't your company stop hiring these people you hate? He said it's because then they wouldn't have enough people. Naturally, this is a contradiction. It didn't matter, of course. His whole personality was built on hating these people.
I think it is that way with a lot of folks. If we penalize employers (like we should, because, you know, the law), then these people can't hate as effectively. That means they might start voting differently.
When they say illegals are taking all the jobs, they mean it's hard to get correct and appropriate pay for their labour because these desperate people will accept much less, which brings down the typical pay for that job. The left blame the employer and the system, the right blame the people accepting those conditions.
And the employers are actually already breaking the law for employing such people. It shouldn't be going beyond that, and yet we never see politicians making that point, because it's apparently a no-no to call out corporations for their actions at this point in American history.
Edit: and also, at least in the case of who I was talking about, they'd never suggest wages were too low across the board. They're secure in their scapegoat. We aren't really disagreeing, I don't think, but this issue runs deeper because there are ideologies at play that do not adhere to logic.
More than once, the anti-immigrant people have succeeded a little too much, and actually gotten all the immigrants away from a given community / given state, and it's created a big catastrophe for the economy and there was a ton of pushback until they made the immigration policy back less strict again (usually, by looking the other way on the hiring side exactly as you pointed out, but still being strict on the coming-into-the-country side, since trying to enforce that side is a lot less effective and basically just accomplishes short-term cruelty without doing much in the long term to stop people from coming in the country).
Florida recently did just that with SB1718 and their agriculture sector paid a big hit. There is an H-2A visa system, but that is not filling the hole undocumented labor left. NPR Link
The story changes changes if employers face federal criminal charges and hard time for hiring unauthorized immigrant labor and if people are rewarded for reports that lead to charges.
It’s harder to crack down on moving targets. Contractors and landscapers stop at a deli, hold up four fingers, and four guys jump in the back of the truck. I see it all the time. Once in a while, ICE comes through and the guys aren’t waiting outside that spot anymore. A few months later, back to business as usual.
Of course that’s what they would do if they actually wanted to stop migrant workers from coming here. They don’t, obviously. No coincidence that the industries who hire the most undocumented migrant workers happen to be owned and staffed mainly by conservatives. Anti-immigrant rhetoric is used as a political tool because it fits the racism and nationalism of the conservative public, but the real goal is to marginalize immigrants so they will accept poor working conditions and can be more easily exploited. It’s the Republican dream - workers who will accept below minimum wage, be afraid to report employers to OSHA, no medical compensation for injuries, no overtime, fire at will, no unemployment. And then it also drives down wages and conditions for legal workers because they know the employer can hire immigrants for cheaper.
When republicans have tried to actually reduce immigrants by targeting employers, it hasn’t gone well for them. DeSantis did so and the big businesses in Florida were basically wtf, dude? Do you not understand this game?
Do you really think a dollar's worth of border enforcement prevents more unauthorized labor hours than workplace enforcement? What about the improvements that would come with additional workplace enforcement, like reducing wage theft, inadequate safety, and other abuses?
You mean what about the opportunity to increase government surveillance? I guess that’s another reason it’s not happening. Not everyone sees that as good.