Ego thing, get speaking engagements, get industry speaking roles or other $, make residency/fellowship look good. For residents/fellows, it's to get jobs/fellowship and pad CV maybe.
For medicine, research of Rx is obviously what leads to FDA approval, indications, all that $$$ stuff... but we don't do that real doctor stuff.
It's neat to see what techniques people are using, but in reality, it's not like a tablet med where every patient takes it the same. I don't get most research for surgery. It's for ideas at best. I can read Myerson's technique for XYZ a hundred times... results won't be same when I do it (different pts, different skill, etc). I can read all about fibula fx nails or arthroscopic ankle fusion, but it may or may not be my best approach to those issues - based on what I have at my hospitals, my skill set and exp and pref.
A few of the long term studies are ok... IMA maintain of Lapidus vs osteotomy, rates of nonunion, rates of amp for TAR, classifications for prognosis, etc.