No one consciously cares, at that age, where people went to school. What happens is that the ones with pedigree are more likely to be selected for leadership positions early on, and appear "on merit" to be worth more, after several years of higher-quality work experience. In reality, they were just able to get themselves promoted faster. After ten years, though, they legitimately have a higher quality of work experience than those without the pedigree advantage.
So you wouldn't be necessarily able to save $100k by hiring people without the pedigree, because even though many are just as talented, they're not going to have the highest quality of work experience. There are plenty of people who'd do just fine, even with the lack of good experience, but you have to be able to find them.
I agree that you've basically nailed the dynamic in the career-development market, but I'll point out that there are a number of career resets you can use to escape it. Grad school. Founding a startup. Independent projects. Moving into a different field entirely.
These often aren't objectively worth it under the value system of your old career, but they essentially throw a monkey wrench into your career and make anyone reading it go "Huh? Why did they do that, and what does it mean for me and my company if I hire them?" And that, in turn, gives you an ability to reframe your story on your own terms. If you're behind in somebody else's value system, it makes no sense to continue molding your career to their value system. Instead, pick your value system and then seek out positions that play to your strengths.
So you wouldn't be necessarily able to save $100k by hiring people without the pedigree, because even though many are just as talented, they're not going to have the highest quality of work experience. There are plenty of people who'd do just fine, even with the lack of good experience, but you have to be able to find them.