Lots of people have college degrees in fields where jobs simply do not exist. Bachelors in Philosophy, Women's Studies, or Underwater Basket Weaving are admirable but do nothing to prepare you to get a job. Most people who study in fields that don't directly correlate to a job end up having a career in an irrelevant field after on-the-job training.
Being educated and unemployed just means that you probably didn't need to go to college anyway.
It's not impossible but I have my doubts.
No, the fact that a worker is more valuable does not mean they will get paid more. "More valuable" only implies a larger upper bound for what the company would be willing to pay were the employee's skills very scarce. However, almost by definition this is not the case for the majority of the labor market: supply and demand have a much larger effect on wages than productivity. Note how productivity has been rising at the same time as wages have been falling in, IIRC, the lower 90% of US household incomes, so this isn't just a theoretical distinction. For most people in the US it's a harsh reality. It is indicative of our fortunate positioning wrt supply/demand that we can even entertain the thought of getting paid in proportion to the value we create.
Small changes in supply/demand can have disproportionate effects on price, so adding a seemingly modest number of educated people to the market could theoretically send aggregate wages tanking far below where they were originally even if each and every employee was individually more valuable to their employer. I don't think the effect will be that extreme, I'm just stating the possibility in order to highlight how dramatic the distinction between value and wages can get.
I did manual labor for a long time before I made the gamble to jump into software development. I had the luck to see it work out, but society can provide resources to help people move into more fulfilling and less physically-taxing careers.
I'll be honest, I love a good day of manual labor, but it isn't physically sustainable. Robots are a much better fit.