The vast majority of AI development is public. There are papers literally every single day to read. In fact everything you need to build Claude and GPT models is public. Thanks to Google, DeepSeek, and all the other research labs. There are more research labs than there are closed shops. In fact there really is only one Anthropic, and lately maybe OpenAI. Google still releases papers all the time on AI.
There are more open source models than closed source models and all of them are accessible without a subscription. Yeah you still need to pay for them, but hey as we build out infrastructure and more time is put into efficient models today will easily run on person compute of the future.