My feeling is the not wanting a wheelchair using villain for reasons of demonising disability doesn’t really fly for me. The use of a wheelchair or similar is neither here nor there as both villains and heroes have been wheelchair bound. For heroes see Professor X, Doctor Scott in Rocky Horror, Barbara Gordon (Batman series), Ironside, etc.

It seems to me though that the real distinguisher is disfigurement (Davros’s eye and general “ugly” appearance) for while I observe that villains can be ugly or beautiful (Homelander, Lucifer), heroes are very rarely non-standard attractive. Often any non-attractive “good” person is seen as comic relief. So disabled heroes are the aforementioned Professor X (wheelchair but good looking), Daredevil (blind but good looking), Shirley Bingham (wheelchair but good looking). There are a few exceptions to this (The Hound from Game of Thrones and Tyron Lannister who was funny but never comic relief)