Well, unless you declare AI consumption fair use, only public domain is fair game, since every single license requires at least attribution. The courts regrettably seem to be buying the line that they are merely "learning" like a human and therefore exempt from the rules. All this ignoring that if a human reproduces something they "learned" close enough, they are on the hook for infringement, and in the AI scenario the codegen user has no sane way to know if the output is substantive and close enough to training material to count, since the origins are so muddled.
I just don't understand the "real" developer to vibe coding scenario. Like, it really sucks, even Opus 4.6, at being completely off the leash. I don't understand how anyone can take what it yields as-is if they ever knew how to specifically get what they want. I know people that might be considered "coding adjacent" who are enthusiastic at seeing a utility brought to life, though usually they haven't that is not quite what they wanted and get frustrated when it doesn't work right and no amount of "prompt" seems to get the things to fix it. They long were intimidated by "coding", but LLM is approachable. Many of these folks "scripted" far more convoluted stuff than many "coders", yet they are intimidated by coding.