What you just described for the baby applies equally to the snake. It's obviously difficult to neatly segment things into innate and non-innate, but the idea that walking is a matter of maturation rather than "learning" is the mainstream view among scientists and has been for a century.

Again, I conceded that you have to "fine-tune" to get good at walking. But the contrast that with say, playing golf. That's something that categorically has to be learnt, we don't see fetus practicing their drive in utero.