The high school science class most strongly correlated with STEM bachelor’s degree attainment is physics, yet only about 20% of high school grads have taken a quantitative physics course according to the American Institute of Physics. The correlation between high school physics course-taking and success in college physics (which is required for every college science and engineering major) is well-documented.
So physics is arguably the most important high school science course for building a STEM workforce, but is the least taken (of the big three of biology, chemistry and physics). I’ve attached a plot of the ratio of the number of students taking a quantitative physics course in high school (from the AIP physics teacher survey) to the number of high school graduates (from National Center for Education Statistics). There is no significant growth since the AIP started taking data (1987).