> but models have become increasingly good at writing.

That's not the impression I have. HN has almost daily articles bemoaning the use of AI to enhance or pad-out human-to-human communication and the comments almost universally agree that the output is bad, using AI to communicate is rude, and they'd rather read the human-written prompt than the AI-"enhanced" version.

I'm not aware of any model that has solved the AI writing problem. Fable 5.1 and Opus 5.5 improve on Fable 5 and Opus 5, but neither are good. They all seem to overuse jargon, misuse literary devices and write ill-fitting metaphor. They all produce prose that is dense and hard to read, but sparse on actual information. Even non-techy people can identify AI writing.