But without a good solid education, moving to new jobs becomes hard. So if the local job dries up how do you get a new one if you don't have a decent education?
Here's the problem. The issue with jobs in the US today is not about education per se, but about fungibility of jobs.
A "fungible" job, or item, is one that can be exchanged equally at no loss or differentiation. (A US dollar bill is fungible, for example, because any dollar bill is equal to any other regardless of its source, condition or owner.) If one mechanical piece or the person who produces those pieces can be swapped out without any loss of productivity or quality then it is fungible. And as such it can be produced anywhere at a lower cost.
Education is not necessarily a defense against fungibility. If you have a theoretically white collar job of IT tech support but that job can be done equally well by someone with equivalent education/training in Hyderabad, then your job is still fungible despite your education.
Some jobs cannot be fungible because the quality of the person doing the job. Think of jobs where one person's talent is appreciably different than another's, like athletes, corporate strategists, artists, rockstar programmers, artists, musicians, financial advisors/fund managers, writers, architects or academics. Other jobs can't be fungible because of their requirements to be local, such as healthcare workers, local retail/tourism, or service providers (automotive/building/plumbing/contracting/cleaning/professional services).
So the bottom line here isn't whether you got a C in high school or not, it's whether you left high school early to take an apprenticeship in plumbing - which will probably get you lifelong local employment - or whether you got As in high school and a scholarship that led to a MFA in Medieval French Literature, which will probably get you a lifelong series of Starbucks barista jobs.
Advanced education is absolutely definitely important to a person's likelihood of future earnings. But not everyone is suited to (or wants to) have a college education. If everyone did, then college graduates would have no employment advantage, right? So the obvious conclusion is that it's not so important how much education you have - rather, it's what education you have in a field that people actually have jobs to hire for.