This one dude would show up at my gym on saturdays only. He was a totally obese guy. Three chins, rolls on his legs but strong as hell.
He'd do three lifts, bench, deads and squats.
He's bench up to 5 plates a side, then do deads to 7 plates a side sumo style then do full squats up to 6 plates a side. He was super strong but you wouldn't know it just thinking it was another fat obese guy.
Then on the flip side I see dudes with wicked shape, defined arms, shoulders etc... doing 35 pound curls and struggling. I never understood how they can be in such shape but also being so week.
The one thing I never sacrifice is bad lifting form. I will do full reps, never lockout and never bouce or cheat the weights but then I see some bodybuilding dudes barely do a 1/2 rep with light weight and are just stacked and ripped. Drugs and genetics have a huge role.