See, you aren't listening here, steeve reeves is one of the largest confirmed natural bodybuilders ever and you say "people have figured out how to get bigger arms in 50 years", if that is true why aren't the top naturals of today surpassing his development?
You obviously have been misled by all the juciers into thinking people can get bigger naturally than is possible, understandable as everyone feels that way before they get into natural bodybuilding. Reeves arms might look small to you but he's still one of the top naturals ever, he is literally like the Jordan of natural bodybuilding, and no, knowledge of diet and training hasn't changed enough that thousands of guys are bigger naturally than him now, they're not....