I do feel like the latest codex 5.2 and 5.3 have been really excellent in coding and have been giving opus a good fight. I still prefer Opus 4.6 as my daily driver but specifically for coding tasks I think codex 5.3 is the best, especially when considering value for money.
This is the strongest argument against it, I think. Sometimes you can't easily tell from the output whether someone thought deeply and used AI to polish, or just prompted and published. That adds another layer of cognitive burden for parsing text which is frustrating.
But AI-generated content is here to stay, and it's only going to get harder to distinguish the two over time. At some point we probably just have to judge text on its own merits regardless of how it was produced.
I'd push back a bit on "writing itself isn't that hard." Clear writing is difficult, and many people with good ideas struggle to communicate them effectively. An LLM can help bridge that gap.
I do agree with your core point - the thinking is what matters. Where I've found LLMs most useful in my own writing is as a thinking tool, not a writing tool.
Using them to challenge my assumptions, point out gaps in my argument, or steelman the opposing view. The final prose is mine, but the thinking got sharper through the process.
I think that this requires some nuance. Was the post generated with a simple short prompt that contributed little? Sure, it's probably slop.
But if the post was generated through a long process of back-and-forth with the model, where significant modifications/additions were made by a human? I don't think there's anything wrong with that.