What are the alternatives though, apart from doing nothing?
Doing nothing is a fine alternative. Surgery changes. Wait until a product or procedure hits the market that you're comfortable with. Anything less than high 90s satisfaction rates isn't worth the risk. You want it to be routine and well studied. And, ideally, you want to wait until you can cover up some of the losses of aging. That's right, whatever you get is only going to look good for some time, as facial bones recede with age. Best case, you need more augmentation. Worst case, that s**t separates from the bone and turns into a mess of shards you can never get rid of. Good as new is hard to come by.
The main reason to consider jaw surgery is that the alternatives are often worse and overall it can improve your health despite the problems it may cause. As it happens, it is a well studied problem with high success rates now. Other than surgical risks biggest issues are with fixation problems, easily addressed later, and thinning of bone.