I don't care about the semantics of if he's the best or top 3, 5, 10 whatever. I view players in tiers and he is absolutely in the top tier with McDavid, Mack, whoever else you want to put there.
Fact is, he is the best player the Leafs have had in my lifetime, been watching since the 90-91 season. He might not have the crazy speed and flash of McDavid but he executes such high skill plays with such ease and nonchalance it's an absolute treat to watch.
Assuming they play their whole or most of their careers on the Leafs, Matthews and Marner are going to shatter team records. They will never have the cup count of the old legends but goals, assists, points etc are theirs.