The issue is the output, not the input. If LLMs were just learning from their training set and generating novel output, the same way a human might, then there'd be no problem.

The issue is that generative AI - both for images as well as text - in effect memorize sources as well as learn from from, and can end up regenerating training sources verbatim (or with minimal changes in case of images).

I don't think any US court is going to accept "yes your honor, we copied this copyright material, but we used a TOOL to do it" as a way to avoid copyright.