Well Computer Science is different than picking up some coding skills. I think you mean that latter.
S1 is a CS major today and was all over the various hackathons that were in our area at age 15. He was on stack exchange and reading O’reilly books on programming and algorithms frequently. He was also a top 1% math student and that helped him enter his major from the get-go in college. Having the coding experience meant that he could take a slightly more rigorous track in the starting CS courses. The UC where he’s at offers a slower track for students who haven’t done much coding before. But by the 3rd or or 4th quarter everyone’s fairly caught up and on their way. So you don’t necessarily need a lot of coding in high school to be a CS major. But it helps somewhat. You will need to be strong in mathematics.
S2 is a similarly strong student in math and science. But he isn’t driven to code like S1. I’ve tried to encourage him learning some coding. But it takes a back seat to many AP courses, sports, music etc. And that’s fine with me. I try to encourage them to develop what they love.