Most surgery is not like that, it involves some objective condition. Such as before you had an appendix, now you don't. Before your bone was broken in the wrong shape, now it's the right shape.
Are you sure about that? My impression in the US is that most surgeries are of the subjective nature. And surgeons are far too eager to perform surgery. That was my own experience - I visited an ENT for sleep problems, and the first thing he suggested was surgery, even turning down my suggestion for a sleep study first. I later found out this person lives in a giant mansion, has a nice yacht, etc. and performs a large number of surgeries. I think in the US there are large incentives to perform surgery since it is so profitable.
Key point from the abstract:
>In half of the studies, the results provide evidence AGAINST continued use of the investigated surgical procedures.