Same reason you don't see AI making images in layers etc, its just much easier to train an AI that generate everything in one layer. Training a model with the s

Same reason you don't see AI making images in layers etc, its just much easier to train an AI that generate everything in one layer. Training a model with the same level of quality output that generates multiple layers is much much harder, and of course companies and users prefers the higher quality over having layers, especially since the quality you get with a single layer is still barely passable.