It's funny that this is a question when every college STEM class is taught by people who have degrees that have absolutely nothing to do with being able to teach effectively.
This does suppose there are good jobs in the area, which can be a bit hit or miss especially out in the sticks. Not to say one couldn't move, but moving isn't in the cards for everyone.
Not really. Public school teachers are well paid when you consider pension, tenure and low stability. Working in industry can pay more than teaching but this is not a guarantee. A public school teacher doesn’t get fired when they turn 40, or laid off in a downturn. It’s less about money and more about qualifications. having a chemistry degree is not the correct qualification to teach chemistry in a public high school. The labor market between stem practitioners and stem teachers are really not substitutes in any practical sense.
I've been multiple places were the teachers in high-mobility fields were bad because anyone good at them could move up easily. takes just one bad interaction with a superior or nagging from a spouse and poof.
This doesn't apply to people who love teaching, they're in it for different motivations.
If you were good at teaching STEM, I think you could probably work nearby in a STEM job for more money.