I think McDavid is certainly cementing himself on that Mount Rushmore of a hockey. It's pretty well established that there are 4 players who stand alone at the top of the game. Gretz, Lemieux, Orr and Howe. They were all pretty dominant players in their eras and they all transformed the game around them, He's likely going to make it a top 5 when all is said and done. Just based on hardware alone.
Gretz - 10 Ross, 5 Rocket, 9 Hart, 5 Pearson, 2 Smythe, 8 First All Star, 7 Second All Star, 4 Cups
Lemieux - 6 Ross, 3 Rocket, 3 Hart, 4 Pearson, 2 Smythe, 5 First All Star, 4 Second All Star, 2 Cups
Orr - 2 Ross, 3 Hart, 1 Pearson, 2 Smythe, 8 Norris, 8 First All Star, 1 Second All Star, 2 Cups
Howe - 6 Ross, 5 Rocket, 6 Hart, 12 First All Star, 9 Second All Star, 4 Cups
No Smythe existed during Howe's playing time but he likely wins at least 2 based on stats
McDavid - 5 Ross, 1 Rocket, 3 Hart, 4 Pearson, 1 Smythe, 5 First All Star, 2 Second All Star
He's racking up the points to belong in that conversation in his 28 year old season. Sure he doesn't have a Cup yet and that will be a large knock on him but he's also playing in the hardest era to ever win a Cup. 32 teams in a cap era makes it a damn hard feat to do but he does have a finals appearance and a Smythe to go along with it.