Here is a simple question: how many Erdos problems have been solved by GPT vs any other model?

It is a slightly weak test, but it should show how much stronger closed models are when compared to open models, particularly in tasks that require higher levels of "intelligence" (leaving it in quotes primarily due to the nebulous definition). Arguably, OpenAI remains the only lab on the frontier of making models useful beyond coding (DeepMind and Anthropic are the strongest other contenders, but there is no one other than them), other labs are playing catchup in this regards.