Like it has already been said, there is no way he would have really been able to actually break into the industry.
If he did end up getting big at a younger age, I picture his fame being similar to the likes of Kevin Smith's. Someone who got a cult following, spawned a bunch of sheep/copycats who think they are somehow owned the same success because they grew up on his stuff, and then in the end become a corporate shill.
To come and think of it, James kind of achieved that on a MUCH smaller scale. He did one thing (AVGN) that developed a following, you have a lot of people who think they are owed the same success because they've been watching him for awhile, and James shills for all kinds of low grade shit.