P.S.
The reason why the spear doesn't capture via "ranged" attack is because the units are too close in the "fast" format meaning early-game spear captures were basically kamikaze attacks. By making it so they can attack from afar without jumping into the enemy, they make progress by forcing the enemy to move their piece away from spear range.
It's a similar reason why hammers and spears gained the ability to move diagonally: they need to be able to force progress vs bows that only run from them.