Ask HN: Openrouter Free Models

Hey friends. It's interesting to me that openrouter offers a bunch of completely free models, for example: https://openrouter.ai/mistralai/devstral-small:free ... What's the point of these models ? Who is hosting them and offering these resources for free? What are the disadvantages of these? I understand that they are not the best but they seem good enough to me. Why would I pay to use the OpenAI API when I can use these for free ?