Yes you still need snowmakers on the hill but you need a lot less with automation. If the gun is completely automated you dont even need to be at the gun to turn it on or see what it is doing. It's not useless at all if you know how to use it
Someone has to be on the hill to make sure the gun is making snow. This is not golf course irrigation, the cold temps would wreak havoc with the automated systems. Like I said my experience was 15 years ago but I cannot imagine that freezing temps, water and electronics all working like the 15th fairway irrigation heads has been figured out.