> And no part of the original source code is in the binary output.

It's not about whether the binary includes the raw text of the source, but whether it copies the expressive content. Anything expressive (i.e. copyrightable) in a compiled binary must have come from the sourcecode, so that's what makes it a derived work.

But the same isn't true of LLMs, which are more like "data about their inputs", than "a transformed version of their inputs".