It leads to other things. Pedophilia is a sick state of mind. If you're condoning this, you're a sick fuck too
State of mind is not a crime, actions are.
I am sure this is no more realistic than the thousands of murders I have seen on TV and in movies. Plenty of movies specifically point out that the scenes of animal abuse are CGI and that no animals were in fact inquired.
Playing GTA is not a felony. The whole premise of the game is dumb, but if you want to play it that is your business. It is not a felony unless you steal a real car. Likewise CGI or AI be it of murder or child porn is not the real thing.
I want to protect children, not support authoritarian control over people. Having legal and readily available AI generated images would go a long way to decrease the quantity of harmful child porn.