The first sentence is key. To the extent manufacturing is "coming back" to America, it's not going to bring many unskilled jobs with it. You don't get a good job at the chip fab with an 8th grade education.
And the second sentence is the much bigger picture. Historically, all human societies have had plenty of work for "unskilled" type people. And I mean, actual work. First, societies were largely agrarian, and much of farm labor (as that labor existed in the pre-large scale mechanized farming era) could be done by unskilled/uneducated folks. You don't need a high IQ and fancy learning to plow fields, thresh grain, gather eggs, etc. Sure, you didn't make much or have much, but it was a living. Then, as societies transitioned to early industrial, it was similar -- most manufacturing jobs didn't require high intelligence or lots of training.
The US is no longer an agrarian society.
It is also no longer an unskilled labor-heavy manufacturing society.
Those ships have SAILED, and they aren't EVER coming back. That's true for most such societies (western Europe, Canada, Japan, South Korea, etc. etc.).
So the question is, now that many countries have economically moved beyond having lots of jobs for unskilled types....what do we do with our unskilled types? Yes, there will always be a real number of such jobs (putting on a roof in the summer sun, cleaning out stalls at the dairy farm, all that stuff), but not nearly as many jobs as there are unskilled people to fill them. And, we can't just tell that guy with a 100 IQ (or lower -- remember, 100 is the MEDIAN IQ - half of people are below that, as a matter of statistics) "learn to code! Or be a stockbroker! Get a degree in engineering!" He's not cut out for those things. He will fail. Just like if you'd told Brisket "if you want to make millions, learn to play football like VY!" It wasn't ever going to happen -- I don't have the tools in me.
So, what does that guy do? What do economically advanced societies do with the 50% of their population with an IQ of 100 or below? We haven't even come close to working up a well thought-out answer to that question. And until we do, we're flailing, faking it, and getting it very wrong.