In one of the WhatsApp communities I belong to, I noticed that some people use ChatGPT to express their thoughts (probably asking it to make their messages more eloquent or polite or whatever).
Others respond in the same style. As a result, it ends up with long, multi-paragraph messages full of em dashes.
Basically, they are using AI as a proxy to communicate with each other, trying to sound more intelligent to the rest of the group.