It isn't just the US too. It's the same all over Western Europe.
What sticks in my craw even more is that, to legitimise the process of issuing more visas, companies and governments have to continually say "there aren't enough STEM and IT grads! Do STEM and IT everyone!" knowing full well that there wont be jobs for these kids at the end of it.
Anecdata: I'm in US. Three boys, all graduated Engineers. All have jobs, easy as pie. One had $30/hr part-time remote work during last year of college. Have to move to get the right job maybe, or take what you can find, but for various reasons they're all very happy.
My Niece is in a field that's chronically low on qualified Engineers - she designs and installs automation in factories. So many facets including mechanical, electrical, industrial, chemical, process, thermo, etc. You have to be an all-rounder to get the job. So they work her flat out every minute she can spare (lives in hotels in remote cities for weeks during installs).
Other niece does lithium-battery development for startups in Silicon Valley. They keep going under, but no problem another one starts up the next week. Got all the work she can handle.
Wife's niece does biomedical research, never been a day without work. Canada, East Coast US (Yale actually), then a regular job with Govt.
Anyway, of the 13 siblings and their cousins, exactly 1 has ever had a day of trouble with employment. So all the talk about 'over-supply' might be exaggerated.
There's a reason anecdotes are useless in these kinds of discussions. Your family probably benefited from network effects: one person gets a job, then provides industry contacts and references to the next, and so on. Your family's tremendous luck should not be mistaken for a reasonable expectation.
Someone will be along with an equivalent tale about how they and everyone they know looked for a STEM job for years and gave up. That's why anecdata isn't actually a thing.
Exactly one case of 'network effect' - one brother got little brother hired on at startup as intern during the summer. Others all lived at far ends of the country from one another, in entirely different fields.
There're other effects, things labeled 'white privilege' or 'middle class ethics' I imagine. So no, not a recipe for escaping poverty or anything. I was the son of a dirt farmer in Iowa (like my sisters and brothers), but worked in Silicon Valley when young so my boys didn't have the disadvantages I did.
Don't get me wrong, I know that some people have major success and I'm glad that they do (I don't think 'white privilege' has anything to do with it as you contend below, as I have as much anti-anecdata as yours which also involves white people).
The data is all out there with regards to the level of unemployment and underemployment amongst STEM and IT grads, the number of people who have to seek employment in alternative industries, and the level of stagnation of wages in the industry. It's not at a level which indicates systemic failures, but it's significant enough to raise questions.
Both "there aren't enough STEM and IT grads!" and "I can't find a STEM job" can be true if candidates aren't willing to relocate to where those jobs are. Despite being one of the most remote-friendly jobs possible, tech is still frustratingly regional. It's amazing how many people will opine on how expensive San Francisco is and how they'd never want to live there and then complain about how scarce tech jobs are without seeing their own hypocrisy.
This doesn't condone what the body shops do, but I don't see a problem H1-Bs being used to address regional shortages in the labor market. But the program absolutely needs to have a regional component given that the scarcity of talent really is regional. We should not be issuing H1-B visas to work in cities where US workers can't find jobs. And H1-B priority should be given to companies that employ the lowest percentage of H1-Bs. With a few other provisions to ensure similar pay, this would destroy the companies that rely almost solely on H1-Bs without hurting tech companies that legitimately need H1-Bs to address the difficulty in finding talent.
What sticks in my craw even more is that, to legitimise the process of issuing more visas, companies and governments have to continually say "there aren't enough STEM and IT grads! Do STEM and IT everyone!" knowing full well that there wont be jobs for these kids at the end of it.