In the late 80's- early 90's I saw a lot of top guys train. I was young and all I cared about was how much weight they were moving. I remember one time training next to Shaw Ray and he was doing curls with 35lb dumbbells. I was so proud of myself that I was standing next to him using 40's. I paid no attention to the fact he had 18" arms and mine were like 15" at best. I would see top guys like Dennis Newman and Troy Zuccolotto squat and never go north of 315lbs. Instead they would pump out reps of 15+ per set like a piston, generally staying in the middle portion of the movement, never locking out.
I was disappointed that the BIG guys were using such light weights that I joined a powerlifting gym. This was a night/day difference. Now, I saw really FAT guys squatting a LOT of weight for 1-5 reps. The weird thing was, most had skinny legs. Then I saw skinny guys deadlifting a ton of weight. Although there were some muscular guys there, to the casual observer many looked like they were recreational lifters at best. Nothing like the physiques of Ray, Zucco, Newman etc. I grew to think those guys were mirror athletes and I got deeper into powerlifting. I got pretty darn strong for a natty guy (3x bodyweight squat, 3x bodyweight DL) but I only weighed 155-165 at any given time. Unless you saw me in the gym, most people didn't even know I lifted weights.
And this was my mindset for 20 years or so until I reached the age of 43 and broke all my PB's in powerlifting. I walked off the platform with herniated discs, a bum shoulder and an unimpressive physique to look at. In a flash, I had a paradigm shift and thought what next? What is my end game? How much more weight do I need to move and at what cost? So I started training like a bodybuilder. I use WAY LESS WEIGHT. I use FAR MORE REPS. I focus on mind muscle connection. And despite being a seasoned lifter and 43 years old, I was able to pack on over 15lbs of muscle in a couple years. I am much "bigger" now, actually a bit leaner and I am 51.
I don't care what the studies show, for HYPERTROPHY there is something to be said about using moderately heavy weights, in a moderate rep range while focusing on mind/muscle connection that trumps moving the most weight you can from point A to point B.