Yeah, people are, and maybe too quickly. The line of thining often is, if a guy was KO'd, he be KO'd again, especially when it's a fighter better than Piriog. But to be honest, I'm not counting out any Jacobs success. Highly talented, speed, and power; three excellent boxing attributes.
I think the best success for someone with a punch against GGG is to really work his body. He seems to spin off back on the few occasions someone actually did this. Jacobs can dig...so work the body hard..then see what he can do after the 5th...apart from that...RUN!
I think if you have supreme boxing skills (Lara comes to mind) you can UD GGG. Not saying it would happen but thats the best chance at beating him is being super skilled.
I don't know that he is better than Pirog was. The Jacob's fight was the last fight where Pirog's back wasn't a significant issue. So we never got to see what he could have blossomed into.
Alot of people thinks ggg is better base on the competitiveness of their title defenses, in particular Isida.
1) Golovkin is going to ram his jab in Jacob's face and play distance games with him until he lands a missile, then, goodnight. He's not going face-first into Jacobs. Look a GGG's early stuff. He LOVED countering guys and boxing. Sanchez changed his style. For the big hitters, Gena dusts off the boxing skills. 2) IMHO the only way to beat Golovkin is to have an iron chin, great workrate, and to crowd him. Take away his leverage and turn it into an inside fight. Golovkin still works guys over inside, but not nearly as badly as at range.
As I stated, we don't know what Pirog could have been, because Jacob's the last fight where Pirog's back wasn't a significant issue. It was pretty much fvcked up every fight after that.
GGG didn't take them shots from Brook on his own, he had no choice in the matter. Brook was just good enough to get them shots off.