- They have better just stuff, but aren't release it yet. They are at the top already, it makes sense they would hold their cards until someone got close.
- They are more focused on AGI, and not letting themselves get side tracked with the LLM race
- LLMs have peaked and they don't want to release only a minor improvement.
This hypothesis has a curious habit of surfacing when OpenAI is fundraising. Together with the world-ending potential of their complete-the-sentence kit.
FWIW OpenAI seems to have a corroded definition for AGI that is essentially "[An] AI system generally smarter than humans".
They don't seem to use the typical definition I'm used to of some variation of autonomy or (pseudo)-sentience.
So their LLM race is the race for AGI