The arguments presented here look suspiciously like the arguments scribe classes of old used against the masses learning to read and write.
Seems like we’ve gotten to the point where sloppy writers are worse than LLMs and assume that all “meticulous” writers are LLMs. The only convincing “tell” I have ever heard tell of: characters such as smart quotes, but even those can just be a result of writing in a non-standard or “fancy” editor first. I’ve even seen people say that em dashes are indicative, I guess those people neither care about good writing nor know that em dashes are as easy as option + shift + hyphen on a Mac.