Kind of missed the point...OP was referring to whether prestige matters when it comes to pursuing a competitive speciality as in getting accepted into residency and the answer to that is, it MAY help coming from a "top ranked" or what is considered a "prestigious" school, to say otherwise is simply not true. You are talking post residency, that's not what the OP was referring to.Prestige only matters if you want your career to be in the ivory towers. 90% of the rest of practices/hospitals/employers/partners/patients don't care.
I know a handful of highly published, ivory tower pedigree surgeons that I wouldn't let operate on me or my family members.
Of course, having attended the "ivory towers" does not mean you have become a great surgeon as you note, but that could be said for anyone, regardless of school pedigree.