Right out of the gate let me say that I'm a huge advocate for STEM literacy. Developing an appreciation and understanding (and, if we want to go all in, an adoption) of logical, rational, mathematical worldviews in kids and the general public is an important personal goal for me and an essential part of the mission of formal and informal educational institutions.
I'm also a huge advocate for general academic literacy, including the arts and humanities. STEM in isolation is not an ideal goal, but that's another piece.
But we often hear the narrative that STEM literacy is declining, and that our mission is to fight that decline lest the general public becomes ignorant and afraid of the world around them. But here are three questions in response to that claim: 1) Can you actually reliably measure STEM "literacy"?, 2) Is it really declining?, and 3) Is that the true motivation of our mission?
I'm always wary of disaster narratives. You know the spiel: there's a huge problem in the world, and we're the only ones who can solve it! If that's the case, what happens when we accomplish our goals? If everyone in the world were STEM literate, would we close our doors and turn out the lights? If STEM literacy began to climb, would we scale back our initiatives? By arguing that we only exist to fight a problem, we set up a perverse incentive: we can only survive as long as the problem does, which means the problem must always exist too.
Instead, we can motivate ourselves with a much more simple approach. We can claim that STEM literacy is an intrinsic good, something that is worthwhile and valuable (and being the good scientists that we are, we can even provide evidence to support this statement!). It doesn't matter if that literacy is declining or growing - our mission stays the same.