I did this line of work for about 5 years; 5 - 6 days a week, 8 - 12 hours per day.
It looks worse than it is. Ok, so it is as bad as it looks, but the body is rather resilient.
Some tissues you don't want to be unduly rough with, such as liver, bowel, or nerve tissue. But everything else is pretty tough and resistant to injury. Being overly delicate will not necessarily result in a better surgical outcome, but it can extend the length of the surgery and consquently the risks associated with anesthesia. Surgeons train for this stuff for years and become adept at balancing technique with speed.
As for things like hip replacement surgery, well, there's just no easy way to go about that kind of thing without hammers and chisels and power tools. Bones and joints are strong as hell.