I have rarely met someone with a STEM degree who was entirely unable to get a decent paying job.
It is not unreasonable to say that some degrees are not as valuable as others and will be more likely to struggle financially. Its a game of statistics. You are more likely to struggle financially with a degree in philosophy than a degree in engineering. Because even companies themselves when hiring for completely unrelated positions to a persons degree will take into account the fact that the engineering graduate probably worked a lot harder than the philosophy graduate.
But I do agree that the average non-degree or "less valuable" degree holder from the past had a much larger chance of making it out okay than nowadays.