The problem is that people are talking as if Brook was the obvious best welter. He was most likely the best but didn't clearly prove it. If Brook fought and beat 3 top 5 guys at welter, then I would be willing to give him the benefit of the doubt. He beat Porter. That's all. That was his defining win.

And just going by the eye test, he isn't on the same level as GGG let alone he is jumping up two weight classes to fight him.