The fact that you believe sam should AI generate his art shows you completely miss the point of why this man does art. He does the art because he ENJOYS doing it first and foremost. No one goes into art thinking its going to make them money. They go in because they are willing to sacrifice a financial stability in order to pursue something that they are passionate about.
He draws the way he does because he genuinely wants to spend his time doing that. The only reason he turned it into a business was so that he could perpetuate his hobby without having to worry about a side job that only takes time away from it.
If he automated that how the hell is he supposed to enjoy his passion? Everyone focuses on the end result because they aren't artists. No artist cares more about the end result than the actual process of making the art. That's the entire reason they are artists.