First thing I do on a new Mac is move the dock to the left hand side and auto-hide if it's a laptop. With typical screen aspect ratios, you lose so much usable space with the dock along the bottom.
Whether you constantly show or auto-hide the dock, it still has to be somewhere. So if you prefer to have it on the side (meaning it also auto-shows when you move your mouse to the side) as opposed to the bottom, it makes absolute sense to move it to the side.