Or perhaps they lucked into chatGPT and the true prowess of the product function is being laid bare. They've had many failed projects now: that shopping stuff, a web browser, Sora.. the success they are having from Codex wasn't an original idea but a classic-case of copying. Have they run out of steam?

Very much possible. What has come out of Meta organically besides Facebook? Its valuation comes predominantly from the assets they acquired + investments yet to be made that build on the acquired assets.

Google is similarly iffy with product development. OAI is better still, marginally, in terms of delivering a more polished experience.

Also I do regard them stupid, simply because they are not following wisdom that was shared decades ago by someone with an incredible batting average when it comes to innovation: start with the customer experience and work backwards to the technology.