>>> encouraging kids to learn advanced math whenever they’re ready for it.
I think the actual number of kids who are likely to be super advanced in math and continue with that interest past high school is so small that encouraging that interest will have absolutely no measurable effect on how the rest of us fare in school or life. Yet it could have a great effect on the quality of life for those kids, and for the future welfare of society. In fact, being great at math, given the tiny number of people who are, is a drop in the bucket compared to being great at computer programming. Likewise for kids who develop an aptitude for playing classical music.