Thank you for this very detailed explanation! I think between this and the other very welcome replies, I think I have discovered what I didn't understand: that

Thank you for this very detailed explanation! I think between this and the other very welcome replies, I think I have discovered what I didn't understand: that "let it crash" addresses a different set of problems than static types, but that a dynamic type system can still be helpful in avoiding type errors in the first place, if it leads you to design data structures in a certain way.