There are tenfold the people doing gear and training nowadays as opposed to Mentzer's heyday - show me an example of somebody nowadays with a similar build please? Mike's got a unique build, instantly recognisable to anybody who knows a bit about Bodybuilding/training history. His own brother was built nothing like him, so I seriously doubt you can find 'tons' of very similar builds.
Of course Mentzer has a "unique build." Every single person on earth does. Mentzer had good genetics and the self-discipline to diet.
You're right. A lot more kids are on gear today than back in Mentzer's time. However, most have shit genetics and are only noticeable because of the drugs.Bodybuilding remains a niche hobby that is hidden away from the general public which perceives it as nothing more than a laughable sideshow. Why would a D-1 college athlete in gymnastics, wrestling, swimming, football, etc., start injecting himself everyday to be a competitive bodybuilder? Instead of being a hero to his family and friends he'll be an outcast.
Bodybuilding is genetics, drugs, and self-discipline. High intensity training, high volume, low volume, etc., etc., is a all BS. Tax the muscle once or twice a week and eat reasonably well. If you have the right genetics and take the right drugs you can look like a bodybuilder. If you are willing to suffer and not eat for a couple of months you can get ripped.