The one thing I don’t understand is that it appears that she has the ability to move, which makes me wonder why they went with something this drastic rather than use a system similar to what Stephen Hawking had.

Technology marches on.
What Hawking had was state of the art and bleeding edge at the time. And so is this. It’s a step towards something better than what we have now, just like Stephen Hawkings computer setup was something better than being bedridden for the rest of his life.