As much as I want it to be true that progress is stalling, I think Sora and Atlas and the rest are mostly signs that OpenAI is trying to become an everything app via both vertical and horizontal integration. These are just a few of the building blocks they would need, and the business case for targeting an everything app given their valuation seems strong (in that the only way the valuation is defensible is if it seems like they will eat multiple existing business sectors or create new business sectors as big as many existing ones).

why train them: you need strong world sim to get full agi

why release them: make money directly, increase doubt in media, addict users

The cynical answer is that Sora and Atlas are likely to be profitable, and there is no mechanism left by which OpenAI can choose to not do a profitable thing.

A superintelligence would likely interact with a large part of the world via a browser. Building a browser that works well with their AI, seems to me like it helps developing an AI that can do task in the real world. 

It also provides a lot of training data of AI acting as an agent that can be valuable for building superintelligence. 

I'm not sure they really have a strong singular goal of AGI anymore, even if they say they do. The company seems to pivot more and more toward ordinary big-tech style business models, and investor expectations.  "AGI" is one story they can tell to push their ordinary financial agenda forward.  It also allows them to hedge themselves and survive as an ordinary big-tech, in case the whole AGI thing never really eventuates within a few decades.

The simplest answer is progress is stalling. They could have gone for the engagement optimization angle since 2023, but there were promising alternatives then. By 2025, these all failed. Pretraining returns stalled and reasoning proved too inefficient to scale. 
 

I agree with Hank Green that it sure seems like it's so they can start selling ads like a traditional social media company, and furthermore that that sort of behavior doesn't feel like what one would expect from a company that thought they were building an AGI.