That does not mean it will draw the full 120W as I think the power supply will be "over rated"
In an ideal world. In my experience just powerful enough keeps manufacturing costs down. I had a problem with a pal's desktop where he had a succession of faulty HDDs. It turned out his upgrade to a larger and faster HDD increased the power requirement by a small amount which overloaded the puny power supply which was only just adequate for the original specification. There was nothing wrong with the HDDs!
My brother had a problem with his very powerful laptop overloading the seat power supply on his trips to the USA. He resolved it by buying another less power hungry machine for use when flying.