[...] latest models are capable of non-slop code and tolerable prose [...]

We may disagree on this. It can help, but "good" quality you are stretching the point. I would argue that if you stay in the comments section only, any LLM generated text is "good quality", but when you look for good writers, and gets familiar with quality essay, LLM isn't even close to "good".

[...] Anthropic has a slight edge on code quality [...]

As a engineer with some years in my back (enough to have back pain when wake up, if you catch my drift)... The quality level of code is "bad" to "ok-ish"... But far from "good". When you work in good codebases you can see what an good abstraction is. But the LLM can only produce "ok-ish" at best, and this won't save the industry.

If this code generation were "good", we should be surfing in new features for every single product, instead we have more bugs. So I ask the question, did it have a productivity boost?

And I get back to my original question on the post, "Who benefits from this binary view on the topic?"