You realise a lot of top powerlifters don't always completely lock out their bench reps on purpose, right? It can place a lot of strain on the joint and supporting structures.
Also, I believe Stan Efferding would purposely not lockout his deadlifts in training.
A lot of powerlifters also train assistance/isolation movements slow and controlled. It's good to actually "feel" the muscle working and focus more on the movement and contraction than the weight. I know I like it for things like curls, tricep pushdowns, hammy curls, leg extensions, single legged leg press, etc.
Edit: I'm not saying a lot of people don't fuck up/misapply what I described above, however, employed properly, it's definitely not "bro science, bodybuilding garbage."