I suspect model improvement costs exponentially more. Between the fact it's been over a year since 4's release and 4o is only marginally better, and that OpenAI

I suspect model improvement costs exponentially more. Between the fact it's been over a year since 4's release and 4o is only marginally better, and that OpenAI is focusing on other things (Sora, mini models, voice, etc) suggests a "better and more accurate and correct" model is actually really hard.