Today the American Dream is impossible to attain for, I'd say, the majority of people.
It may be that it was just a complete anomaly - in human history, it was never possible to achieve this, barring a couple of decades in one country (USA). And after it, even in the US, things got back to normal. It may be that your parents' generation was the luckiest generation in history.
Instead, we let a housing cartel (boomers) forbid any new homes.
Hardly. The people who are not yet on the wrong end of it play nice with it in order to not end up on the wrong end of it, those on the wrong end of it would actually prefer to suffer less, have a decent life and all that. It's just that we're standing on their throats and don't have very good ears, so it can be hard to hear.
So those jobs exist, just not enough of them.
Being steadily employed directly out of high-school makes it much easier to obtain a mortgage and find a home in a low CoL area.
Your last sentence shows how readily that assumption leads to dismissive blame. That doesn't seem like a road to progress for anyone.
Learned helplessness can be unlearned but a burden alone
There's also an element to your original post of "why don't depressed people just snap out of it?" which is, as always, risible.