I'm pretty sure math is the most poorly taught subject out of all of them. Social studies, current events, history, literature arts are mostly skills most people use everyday.

Math is important so every school is required to teach it however not many schools can. The issue with math is there are never going to be very many good math teachers as that would require many more people who know math. How many adults even know math beyond basic arithmetic?

I think the economic returns to "decent understanding of X plus decent communication skills" are much higher when X is math than when X is art or language or history, so you need a greater passion for teaching to select it in spite of that fact, and this shrinks the pool of good math teachers relative to other subjects.