Bariatric surgeries are considered by some experts (mostly surgeons?) to be the most effective way to treat or cure type 2 diabetes. They are effective, assuming you survive the original operation and potential complications, which may require further surgery.
From JAMA Network:
Among patients with type 2 diabetes and obesity, metabolic surgery, compared with nonsurgical management, was associated with a significantly lower risk of incident [heart attack, ischemic stroke, and mortality]. The findings from this observational study must be confirmed in randomized clinical trials.
Steve Parker, M.D.