Programs that do multiple things are not simple, so successfully using or understanding what they do is less likely to be possible for you. I expect that wanting to avoid interacting with many programs will lead a person to use programs that are nonfree more often than they otherwise would, so it would be more likely that a program controls the users.
I’ve used reddit.com before but I never made many posts or comments and I haven’t used it in years. I’m pretty sure there was a period where I visited it regularly though.
I don’t think I’ve ever posted anything with facebook.com or twitter.com either. I never browsed them for fun, and if I want to coordinate with someone in my family I just contact them directly. I do use youtube.com a lot though.
I tried using pleroma but I haven’t used that in a while either. I prefer lemmy much more (probably because posts being different from comments provides more structure).