Kai Greene one of the best bodybuilder in the game today knows obviously A LOT about hypertrophy and growing huge amounts of muscle. As Kai explains it is not of any importance to him how much weight he can bench or lift, his primary focus is contracting the muscles the best way possible for hypertrophy.
Don’t get it twisted weightlifters are those who are constantly trying to lift heavier weights and are not doing it to build muscles. Bodybuilders are those who care about building muscles and are not concerned about how much they can lift or how much they bench.
This is a common misunderstanding we see in gyms all the time, guys bragging about out lifting someone who is bigger than them. What most ego lifters do not realize is that bodybuilders are not concerned about setting a new bench PR their only concern is building a bigger, better proportion physique and the best way to do that is not by lifting as heavy as they can.
Watch this interesting video below and it should answer the question clearly what the difference between weightlifters and bodybuilders is.