I believe there is still a major court case underway to decide if AI trained on copyrighted data makes it's derivative works copyrighted too.
It's an important court battle because it will set a precedent for every other AI related case for all the other AI companies
The way we socialise has changed to the point where it's normal to talk to people over text chat. This leaves a footprint that talking face to face with someone does not.
In addition to other privacy concerns, I don't want things I say that I would've gotten away with had I spoken it to my friends in real life, to come back and haunt me, either by a platform having a massive data breach, or it being used as evidence in a legal case against me.
On that last point, I'm not using chat services to organise crime, but taken out of context, any message I send can paint a picture that I'm an awful person and change some jury's opinion of me. This isn't something I want to think about before sharing a dank meme to a friend on discord.