Why haven't we seen any open-source alternatives to GPT yet?

I am genuinely confused why we haven't seen any open-source GPT alternatives. I am not talking about platforms like Anthropic, DALL-E, Hugging Face, Tausend, or Perplexity, which are closed source. <br><br>I am talking about a project like the Linux kernel, which is open source, that people can contribute to. We have seen this in multiple projects before. I see this as a major issue if no one is allowed to contribute to a project.