Are these entry-level positions or do they required experience?
There's a huge difference in the job markets for entry-level jobs (education required, but no prior experience required) and for jobs that require experience.
When you're dealing with entry level jobs, the candidate pool consists of everyone who obtained a college degree in the field. When you're contemplating experience-required-jobs, the amount of competition is limited by a huge barrier to qualify for those jobs. A person may have the intellectual ability to perform such a job, but if he had been unlucky enough to have been unable to obtain an entry-level position in the field, he cannot compete for the experience-requiring job. It's thus possible that the number of people who trained to enter a "good field" could thus be much higher than the number of jobs that allow entry into the field. In other words, those who were able to get the experience might simply be lucky or have great interviewing ability for having been able to obtain it.
The legal profession is a great example. Associate attorneys at large firms with two or three years of experience might be hot commodities, but that does not necessarily mean that the field is a meritocracy or that anyone who works real hard in law school and who has ability will actually be able to find a job in the profession. Because 3 or 4 times as many new lawyers are produced as their are jobs for them, most are never able to enter the field. But for those who are able to at large firms, the job market two or three years out can be great.
Contrary to the "I've got mine, F-you" dogma, a lack of skilled jobs for college graduates in a great many fields, including those vaunted STEM fields, still exists.