How do you know there is no proper proofreading? There is no way to tell, is there? Just because content was generated by an LLM doesn't in itself mean that it wasn't proofread.
> We searched and scraped Google Scholar using the Python library Scholarly (Cholewiak et al., 2023) for papers that included specific phrases known to be common responses from ChatGPT and similar applications with the same underlying model (GPT3.5 or GPT4): “as of my last knowledge update” and/or “I don’t have access to real-time data” (see Appendix A).
If noone bothered to even spot and remove these, you can be pretty sure that no human ever read the whole paper before publication.
IMO, at this point, AI is very necessary as a pre-reviewer to weed out such papers that haven't been proofread. This is at both the journal as well as the preprint levels, preventing them from getting an audience.