I agree sinus surgery seems like the absolute last resort and is to be avoided if possible.
Look at this way, in China if you go into the hospital with appendix pain they admit you and go in surgically clean the appendix out give you some Antibiotics to be on the safe side you go home with appendix in tact. They would remove it is life and death and it has ruptured. They understand that the appendix is important organ of the body and helps in with flora and immunity. So, this is different mind set.
My friend was sick forever, through grade school and then high school. Suffered from on,migraines, sinus issues, dizzy and tired feeling . Then last year of high school had sinus surgery last went away to college and that did not fix anything. Then stopped all dairy and gluten felt a lot better, Then returned home for summer break made sure to avoid all dairy and gluten , and was sick all over again. Finally they figured it out it was the cat's all that time that were causing her sinus issues, The parents always owned three cats.
My point is that dig deeper and see if you figure out the cause.