Everyone has a genetic limit. I'm not going to bench press 700 pounds. Therefore the set of all things I could do (naturally) in my lifetime to raise it has a least upper bound. QED:)
There's a time for intensity. As someone starts to get diminishing returns, the needs increase for higher intensity, probably higher volume, and higher complexity e.g. periodization or something even more complicated than that. The time for intensity is not when you are just starting weight training, in which case anything will work (but someone should do exercises properly of course.) The time for intensity is doubly not when your primarily goal is to lose weight, in which case the body isn't going to have its full resources to repair itself.
Quoting myself, adding emphasis, "The limit on the amount of muscle mass you can pack onto your body is much higher than most people have the will to achieve." A 700 pound bench press is actually humanly possible, as the record for a raw, drug tested bench is 711 pounds. If you said 2000 pounds, then I'd agree with you; I think that's beyond human capacity. But 700 pounds is within human capacity, and your limit is your will.
There's a time for intensity. As someone starts to get diminishing returns, the needs increase for higher intensity, probably higher volume, and higher complexity e.g. periodization or something even more complicated than that. The time for intensity is not when you are just starting weight training, in which case anything will work (but someone should do exercises properly of course.) The time for intensity is doubly not when your primarily goal is to lose weight, in which case the body isn't going to have its full resources to repair itself.