Yes, there are ethical differences to an individual doing things by hand, and a corporation funded by billions of investor dollars doing an automated version of that thing at many orders of magnitude in scale.

Also, LLMs don’t just imitate style, they can be made to reproduce certain content near-verbatim in a way that would be a copyright violation if done by a human being.

You can excuse it away if you want with reduction ad absurdum arguments, but the impact is distinctly different, and calls for different parameters.