Struggling to reconcile the first part of your post with the second AI is extremely good at the sort of writing that sucks, because it writes tight prose, subs

Struggling to reconcile the first part of your post with the second AI is extremely good at the sort of writing that sucks, because it writes tight prose, substitutes character x and related tropes into story archetype y fairly well and it can handle cliches and beats and it can reasonably be assumed will start to get a better handle on overarching structure as the number of tokens it handles gets bigger. Yes, this will allow people that can't write for toffee to attempt fanfic too, and other models will let writers who can't draw illustrate and maybe even animate their stories. But its model of character motivations is limited at best, especially with fresh, original characters, it resorts to cliches by design since its output is literally derived from overlaps with similar concepts and training approval of those overlaps, it doesn't know what a plot hole is, and it can't tell a brilliant, original ending from an atrocious ending. It can absolutely tweak paragraphs a writer doesn't like very much and do absolutely everything for content creators that don't like writing very much and are happy with "good enough", but I don't think the bottleneck to someone like GRR Martin's creative output is that he can't think of lots of permutations himself or type out scenes fast enough.