Actually, the study of S (science) in STEM is common enough that many S graduates find limited demand for their skills (particularly biology, but even physics majors often have to find other work in such areas finance or computers). So, while the study of S is necessary to produce the next generation of scientific researchers, it is not like there is generally a shortage of such.
The job market for E (engineering) graduates is much more in balanced, though economic and industry cycles do affect what it is like at the time of graduation. M (math) graduates seem to have job prospects heavily slanted toward finance, which seems to be growing to a larger share of the economy as time goes on (whether or not that is desirable is another subject entirely). Not sure what the job markets are like for the relatively uncommon T (engineering technology) majors.
But perhaps the biggest deficiency is the lack of understanding of STEM subjects by those who do not study STEM subjects as their college majors. General education requirements and courses in STEM subjects for other majors are often too limited or not well done so that such students may not get enough understanding of STEM subjects as they may relate to their own major fields or to subjects encountered in life in general.