> Once we accept that simply "learning from previous copyrighted works to make new ones" is "infringement"

It's not, because LLMs are not making new copyrightable works.

To make a copyrightable work you must put some creative act into it. Just copying someone else's work does not enable you to claim copyright. But LLMs cannot put creative work into their works, because only humans are capable of copyrightable creation - so therefore it is infringing.