They are selling "AGI"
replacing huge swathes of the white collar workforce
"incremental upgrade for power users" is not at all what this house of cards is built on
They are selling AGI to investors, but they're just selling intelligence to subscribers. And they just made the intelligence cheaper and better.
For all of them, getting access to full-blown GPT-5 will probably be mind-blowing, even if it's severely rate-limited. OpenAI's previous/current generation of models haven't really been ergonomic enough (with the clunky model pickers) to be fully appreciated by less tech-savvy users, and its full capabilities have been behind a paywall.
I think that's why they're making this launch is a big deal. It's just an incremental upgrade for the power users and the people that are paying money, but it'll be a step-change in capability to everyone else.