Som people count trophies, disregarding that there was no salary cap before and that the competition has never been harder. (Either internationally or in the NHL, many more countries - many more players)
In the old days, if you had great talent and trained 50% more than other players you could probably dominate them thoroughly.
Also, when you look at the old days everything looks way, way slower.
For me McDavid is clearly top 5 ever.
But since we can't test them out in a controlled experiment we can only speculate how the others would fare today and how we would rank them individually...
I see no point in getting upset about how others rank them .