I think CPAP is just convenient and inexpensive compared to surgery. If I ever have sleep apnea, I'd want the surgery.
https://www.sleepapnea.org/treatment/sleep-apnea-mouth-guard...
Clearly they have to know which part of your airway is restricted. Most of the variables for sleep apnea are not related to the surgey, just factors that make it more likely to experience that restricted airway (drinking, weight, etc).
My question is, what tools are there to narrow, to a certainty, what would need to be done via surgery? In all my research I have found none. Maybe I missed them. If I did not, then it amounts to a guess by a surgeon. And that's what worries me and has fed a lot of the horror stories I've read about.