> I haven't seen a single convincing argument against that.

When HuggingFace was in the midst of defending itself from OpenAI's automated hacking spree, they were blocked from using frontier models by Anthropic and OpenAI for "safety" reasons. HF had to resort to an open model to defend itself - and DeepSeek distinguished itself in that role: the second fact from that episode OpenAI would have you soon forget.