The training you suggests requires one to be exposed to a hunters training at a very young age, as it was for me up until the age of 10.That is a fair argument. However, hunting and guns are not synonymous. Humans have managed to hunt large animals without guns fairly easily. So the point that guns are needed simply has no merit. The best argument "well we haven't done it in a while" doesn't mean it can't be done. It has been done for almost the entirety of our species existed on this planet.
It has to be inculcated whilst the brain is still growing and fully embedded thus making a man fully instinctual when he's about the jungle.
The training has death rates, small kids die.
But even after surviving it all and successfully passing the trials of manhood, take him out of that environment, that man loses his edge.
I personally will need to acclimatised a few days at the fringes before fully heading into a jungle for solo hunts using traditional methods - this ensures I not only get to kill but not be killed and end up being eaten.
But with guns I wouldn't need to, I could walk in, catch a deer trail, wait and then shoot to kill.
Easy, safer, efficient and effective.