I actually agree with Avante here. Considering the era he played in, Mackey was damn good. Gronk is the most physically intimidating offensive skill position player maybe in NFL history, but the guy gets hurt way too much, and misses way too many important games, for him to really be the GOAT tight end.
Like if Shaq missed 30-40 games every year, and Kobe won les while Shaq was hurt, we’d think differently of Shaq while acknowledging his dominance. At this point Gronk is a liability for his team, where they have to limit themselves offensively to protect his fragile body, and while he’s the most dominant force in the game by far when healthy and fully unleashed, it’s incredibly rare to see that anymore.