I'm aware that with most privacy issues, a lot of people have limited understanding about it. Hell, I'm probably ignorant on many other privacy issues outside of this topic.
Then they know who's the poster (you), they can know your username if they want to. A lot of people use the same username in many places, so unless you use different usernames in different social media, it's still valuable data.
If not that, seeing how the content spreads through social media and analyzing the reach is interesting data by itself.
Look, the point is that I've tried explaining it to friends and family and whoever want (and don't want) to listen.
This post is a rant / wishful thinking as stated as being so, I'm not in the mood of explaining everything again. I've done that in my personal blog, etc.
If you use ublock origin, I find add-ons such as ClearURLs to be no longer necessary.
You can just add url tracking filter like this one maintained by adguard to ublock origin: https://raw.githubusercontent.com/AdguardTeam/FiltersRegistry/master/filters/filter_17_TrackParam/filter.txt