The vast majority of bodybuilders are not growing rapidly. When growth stops or occurs slowly bodybuilders tend to get confused and end up not knowing what to do to stimulate more growth. Since they have tried so many methods and believe they are working out hard they cannot understand why they aren't growing. Well, they are doing something wrong or a few things wrong. Many don't eat enough, especially if they are young active guys. Everyone who gets to the intermediate stage has heaps and heaps of experience and this is why everyone is an expert in bodybuilding. Yes, it isn't that difficult to reach a stage where you look impressive and people know you lift weights. Few go beyond the intermediate level and become huge. When people fail to get bigger then blame the lack of drugs. I hear this all the time. Goodness knows how many guys have secretly tried steroids. Must be millions of fellows. Millions and millions all over the world. What do we find? Most of these guys don't get huge, either! What the!!
What seems like a simple thing to do turns out to be very difficult or a mystery. It has to be the genetics say the hapless trainees on plateaus. How would they know what it is? They don't know but don't blame their training because they have a long history in the gym and know what works for them.
The one thing that complicates everything is motion. Almost all training involves moving. When you move weights you can do it many different ways. For some strange ego reason most people cheat and try to lift heavier weights than their muscles are capable of. I see this all the time. Swinging motions on the lat pulldown. Arms out to the side on pressdowns with rope for triceps, bending and staightening knees during heel raises, and so the list goes on and on. If you are not putting mechanical tension on a target muscle it won't grow. It can't grow! This is where having a good brain helps because it does take a special brain to make muscles grow. If you haven't got that kind of brain then get someone who has to help and guide you. Once motion enters the picture things become complicated and you really can't compare programs because individuals do different things while seemingly doing the same movements.
Your right, the vast majority stays inside of the intermediate stage because they do not understand systematic fatigue and how to properly use periodization. The dual factor theory is universally accepted everywhere except in the bodybuilding world.
You have guys correlating perceived effort with growth, doing all sorts of sets and reps yet unable to understand planning for progression and homeostasis disruption. In other words, guys train like shit for the most part.
You have to properly load and deload to let fatigue dissipate. Eventually, if the program allows you to progressively add weight, it will stop and you will need to taper. No taper=no progress.
When you over reach, you are done and you must deload in order to progress again. Guys have that confused with reducing the number of sets and reducing frequency to equal more progress, which does work for awhile.
Anyway, when you are over reaching or never tapering your training, you end up spinning your wheels and you eventually over train. Steroids fix this, then plateaus are overcame by simply upping the dosage and manipulating the diet. However no supplement will overcome this.
Basile, if you do not understand this concept no amount of direct tension will do anything.