Back when I had more free time, I used to do a lot of "STEM outreach" --- judging science fairs, busing kids to NASA, that sort of thing. In my mind, the idea was to show science and technology to kids in a positive and realistic way, so they had good information to base a career decision on. I never tried to talk a kid into being a scientist. The only persuasion I did was to convince kids they could be scientists if that was what they really wanted. I also hoped to create an appreciation for science in kids who weren't going to be scientists (i.e. most kids), but who would likely come to have some influence over whether science will continue to be supported in our society.
The truth is that the vast majority of people would be unhappy with a career in science or technology. Not only unhappy, but disappointed, because of what they hear about how great STEM careers are supposed to be from various interested parties like big companies and universities.
First, it is totally untrue that there is a shortage of scientists and engineers. On the whole, it is no easier to get and keep a job in STEM than in any other field that requires a college degree. Certainly, companies would like as many STEM workers as possible to choose from, because then they can get more productive workers without having to pay high salaries. But true shortages are really rare - the ones I can think of were for aerospace engineers in the late 1950s and for anyone who knew anything about the Internet in the late 1990s. At those times, you could get multiple offers and signing bonuses. But even in times of high STEM unemployment, you still hear about this supposed worker shortage. People have heard it for so long that they don't question it anymore.
I do believe that having more STEM workers productively engaged in advancing the state of the art must be good for the country. But it is not as if there are projects going stale for lack of engineers. The investment just isn't there. That is a totally different problem than not having enough workers.
Another issue is the way STEM careers are portrayed by well-meaning adults who want kids to go into STEM. Here's a site that presents storm chasers, robotics researchers and and astronauts as sort of typical STEM careers. The reality is that most STEM jobs are nowhere near as fun as that, and the competition for the really fun jobs is very stiff.
When I was thinking about a career, I had the idea that going into STEM was sort of a short-cut to a high-prestige, professional career like law or medicine, but without having to go to graduate school. I didn't really know any scientists or engineers when I was a kid, so all my knowledge came from the media. My "STEM outreach" work was partly to help other kids not be in that position of ignorance.
With a bachelor's degree from a "not top ten" university, you are not going to be designing or inventing much of anything. I know, because I was there once. You're going to be doing things like keeping track of which parts go on which washing machine or lawnmower, figuring out how to save 3 cents a part by reducing the thickness of some material, and writing user manuals.
Now, doing that for a living maybe is not so bad compared to, say, road maintenance or moving boxes in a warehouse. But when you look at what it takes to even get a bachelor's degree in engineering, it doesn't seem worth it. For example, to get a BS in engineering, you'll have to pass a course in differential equations. I reckon that you need to be in the top 5% of mathematical ability to even stand a chance of doing that. And once you do, wouldn't you want to use that knowledge? In the job I had with only a bachelor's, I barely did algebra, let alone calculus. I had a calculator, but only ever used it to add up costs! Probably the average accountant does as much math as BS engineers. A lot of engineers got suckered into getting BS degrees, thinking they'd be designing Corvette engines or something. Twenty years later, they've designed a lot of pipes and brackets and they're wondering where the time went.
So getting a BS in engineering is no short cut to professional prestige. To get the really fun jobs, you need a Ph.D., which is certainly harder than law school and might be about as hard as med school. I think you have to be smarter than the average med student to get a STEM Ph.D., but you probably don't have to work as hard unless you have a real asshole as a research advisor. You do get paid (very little) to go to grad school instead of having to take out loans as in law or med school. If you find yourself paying your own way through a STEM Ph.D., you should really just forget it. Go to culinary school or become a llama rancher.
It might be possible to short-cut that process by getting involved in startups. But that option is not available to most people; it certainly wasn't to me. You have to have savings or rich and generous parents to tide you through those lean times when your startup is unable to give you a paycheck.
Having thrown all this cold water on STEM careers, you might be expecting me to say I don't like my job. On the contrary, I love it. And to any kid who really likes science and technology, I say: you'll love it, too. But you need to be ready for a long slog. Like the song goes...