Very, very little labor is unskilled. In almost any work there is a massive difference in quality and speed between someone who has been doing it for <6 months vs. someone who has been doing it for >3 years.

My theory is that "unskilled labor" was a term of propaganda invented by an earlier generation of business leaders in order to publicly devalue many labor-intensive roles. That generation knew that it was a lie, but the business leaders that followed were taught that "unskilled labor" was axiomatic, and essentially "drank the kool-aid".

The result of this is that the labor pool for many disciplines has been hollowed out because it's no longer financially sustainable for workers to build the skills needed to excel in those roles.

Yes, it's propaganda. If the corporatists can convince people that a previously well-paid job (working in a slaughterhouse, for instance) is actually "unskilled labor," they're one step closer to convincing people it should pay less, and that it's a job no one you know would take so they have to import cheap labor to do it.