It seems like people are looking at raw numbers but are severely overlooking the sheer utility he now has. First of all, his weapon fire. This is just a straight buff. Perhaps the skill ceiling was lowered, but now he does more consistent and reliable (and greater) damage at all ranges instead of having the mystery spot in between ranges that was there just to be annoying.
Hook is the same, so no change. Which brings us to the trap. This alone changes his play style completely — there is so much you can do with it. First of all, it’s free damage. 150 and a slow in an AOE is no joke, and he can shoot and hook pretty much instantly before/after so there’s no downside. But the main advantage is tactics — Hog has so much control over the trap it’s not even funny. Throw it behind supports to cut off escapes, hide it behind corners for ambushes, throw it directly in a firefight, etc. Again, none of this was possible before so it’s a straight buff.
And finally, breather. Yes, it’s a little weaker, but the fact that it can’t be cancelled is huge. This alone is a direct counter to CC like sleep dart and anything else that would normally cause it to whiff. Now he can just tank a stun and be back to healing. Or tank a big ult and immediately hook them once they’re vulnerable instead of walking around like an idiot while he waits for the animation to finish.
I think people just don’t like the idea that pigpen is now as important as hook, so the skill ceiling has shifted to that interaction compared to just the primary fire ranges. So he is played more tactically now. But he can absolutely wreck the back lines if he has good positioning and can stay alive the whole time. He’s still the best tank at picking off supports — and yes, Ana still counters him somewhat but that’s true of everyone (and Ana’s win rate isn’t even that good).
He’s still a tank, so of course he still suffers the same fate as all other tanks. His rebreather at least doesn’t get canceled anymore which is the biggest positives.