I have no way to net this out or prove it. But to me, this is like saying all the QBs the Browns ever drafted before Baker were busts. To me, talent is important, but team culture and a healthy system is far greater.
I'm a KC guy, so I'm fond of Mahomes, and truly think he has some special things to him, but believe if he goes elsewhere it's not quite the same as the situation he had/has in KC and other QBs could've had similar success.
Or a basketball analogy. Kobe ended up being one of the all time greats, but am a firm believer that you switch him and AI or McGrady with 99-02 Shaq and the results are just about the same. Kobe carrying a team that loses out Shaq and a dynamic scorer.