4o does not stand for ‘for all’:
> GPT-4o (“o” for “omni”) is our most advanced model. It is multimodal (accepting text or image inputs and outputting text), and it has the same high intelligence as GPT-4 Turbo but is much more efficient—it generates text 2x faster and is 50% cheaper. [1]
[1]: https://platform.openai.com/docs/models/gpt-4o
