That already didn't happen, regardless of AI. The thing about freely sharing knowledge is that people take that knowledge and use it to build further knowledge that helps you.

You might say that the fact LLMs are being provided as services by big techs invalidate that. But some people taking the provided knowledge for themselves has also always happened. More importantly, though, is that big tech provided LLMs aren't the only way to access the technology. Open weights and local models exist.