Dogs and wolves evolved from a common ancestor between 9,000 and 34,000 years ago, before humans transitioned to agricultural societies. However these days dogs are more closely related to each other than wolves, regardless of geographic origin. This suggests that part of the genetic overlap observed between some modern dogs and wolves is the result of interbreeding after dog domestication, not a direct line of descent from one group of wolves. (
Genomes of modern dogs and wolves provide new insights on domestication | Science Codex)
Dogs are one of the most, if not THE most, human-manipulated species on the planet. We basically designed and created them. So there is no reason for me believe that all dogs should be eating raw food or that there is even a 'natural' diet for a... basically unnatural species.
Also, dogs systems are not 'evolved' to eating dry food per say, as dry dog food has only existed since the early 1900's and dogs have been around much longer than that. I would say they're more evolved to do well on.... whatever they get. lol. I've read a few things that seem to indicate that farm dogs were basically fed leftovers or scraps (i.e. culled or dead livestock) or in some cases sort of a cheap corn meal mush. People definitely were not going to feed dogs any kind of valuable food when many were struggling to feed themselves.
Now the thing is, of course some of these dogs likely weren't thriving, and many modern advances have been made in today's world and what we are willing to do for our pets and how they are treated in today's society vs. back then. But it's always questionable how much of it was diet or simply lifestyle.
There's simply too many things to factor in to really know for sure what's better or worse at this point. But I think there's room for all views!