there are 2 different types of punching power breh
the sharpshooter, explosive type of power, usually these are the guys who possess one punch KO power but they usually not pressure fighters but rather boxer-punchers, ambush fighters, idk... more rangy fighters. They gain their punching power from their motion and speed and their punches are sharp. However these fighters often just throw one-twos and then jump out so the opponent has more time to back down and recover. These are usually not the fighters you see just walk down thier opponent ad beat him up with accumulation on the ropes.
Thurman is this type of fighter, he punches strong as fukk when he can gain leverage on his punches but he isn't the type of heavy handed pressure fighter who just gonna walk you down and beat you up, up close, on the ropes, etc... with accumulation. As Thurman's opponent's went up in quality they more and more could absorb those 1-2 sharp power punches and could step back and survive cause Thurman didn't walk them down. You could see how he almost KO Guerrero but after that Guerrero went up close and was more comfortable there. Thurman isn't the guy who's gonna KO your ass in a phone booth war, he is the most dangerous when you're mid range/far from him and he has space to jump at you.
The other type of power are the guys with simply heavy hands and thudding power. They usually destroy their opponents with accumulation of shots, they are usually pressure fighters. Their punches can snap too but generally they rather work mid range or up close with short hooks, uppercuts, etc... than jumping in with straights or wide shots like the first category.
some fighters from the sharpshooter, ambush type: Thurman, Haye, Stevenson, Wilder, Rigo
to the heavy handed type: Joshua, Spence, Golovkin, Gassiev, Matthysse, Beterbiev