I didn't really want to say anything about this but it's got to a bit of a point now.
It's blindingly obvious when someone's used AI to write their fics or drabbles for them. While I don't care if people in fandoms do, it's only fanfiction and it's done for fun, what I do care about is people trying to pass it off as their own writing.
AI steals from actual authors who have spent years, sometimes decades, honing their craft, and a lazy good for nothing feeds a robot a prompt and claims they wrote what it then spits out, or posts it without tagging it properly as genAI, which is lying by omission.
If you must use genAI in your posts, tag it as such. There's no shame in using it for fun, but if you don't tag it, you're stealing from better authors and lying about your craft. Better yet, write your own work. Your own effort will always surpass anything a robot recycles from superior authors.
We can always tell. We always know when you use AI.