In a similar way that a scalpel helps execute a surgery that's inoperable without a scalpel. There's a lot of difference between a scalpel and a 'robot' but its a tool nonetheless.
TL;DR: old human hand based surgery breaks the jaw to get to the area of the throat where the cancer was. Causes lots of complications after; or is simply deemed too hard.
The robot is more dextrous and thinner and can do the surgery without breaking the jawbones.
In other words, I agree with what you are saying.