Burr was absolutely carried by his loud energy taking decent jokes to high levels.

But his big source of humor was being a lot more over the line than most comedians would be willing to go. Stuff that seems blase to the kind of guys who'd be on this forum, but was huge and different to hear at the time he was saying it. Especially saying on TV at that. So its very much a "you had to be there in the culture of the time" thing about what made him special. Without it, he is just loudly saying shit.

That's also why people have this extra affinity for calling him out on his change. Because he was actively calling out the shit he now participates in, and helped a lot of people form their ideas about disliking it themselves.