That might be a stronger way of putting it than I would. The canonical example is iterator chains with complex logic compiling down into vectorised and unrolle

That might be a stronger way of putting it than I would. The canonical example is iterator chains with complex logic compiling down into vectorised and unrolled loops. Powerful logical abstractions are used by the compiler to generate code that does what it says to do without the runtime cost of closures or whatever other logical but not mechanically necessary things you have. Iterators can't go out of bounds, so the compiler can elide those checks. There are still some runtime costs at the intersection of safety, ergonomics, and performance. Bounds checking, overflow checking. But they have escape hatches and are relatively rare in the language. Most things do compile out.