There's a lot of subtle human interaction that AI is really going to struggle to identify. While it may be able to cobble together something that looks like a game, making it satisfying for a human to play is another matter.
Likewise there are serious issues with originality as mostly AI art seems limited to mashup and distorted copies.
Even the AI adventures aren't stand alone games. They work by having the AI generate each new scene in response to your input in the previous scene There's very little continuity. It's likenplaying D&D with a senile DM who can't keep track of the world.