These posts are public, everything is public here, anyone could use this data for any purpose.
Usually when people talk about privacy violation, it is about selling personal data, like legal name, email, home address, private encrypted messages, etc. Stuff that is highly sensitive and pretty much wasn't intended to be known by anyone except a certain party.
If you don't want to make your posts available for everyone, there is a simple solution - stop using public social networks 🧐