These are questions that, again, are tread pretty well in the copyright space. ChatGPT in this case acts more like a platform than a tool, because it hosts and can reproduce material that it is given. Again, US only perspective, and perspective of a non-lawyer, the DMCA outlines requirements for platforms to be protected from being sued for hosting and reproducing copyrighted works. But part of the problem is that the owners of the platforms are the parties that are uploading, via training the MLL, copyrighted works. That automatically disqualifies a platform from any sort of safe harbor protections, and so the owners of the ChatGPT platform would be in violation.
I was “good at math” in school and all through uni. Discrete mathematics crushed me.