Owning your data would mean that you as a user could opt into the social graphs that you want to be a part of, and pull that data out whenever you like. It would also mean that competitors could build more privacy-focused alternatives, perhaps a stripped down social media experience that doesn't allow sharing of articles for example. Maybe your friends still like to share memes, and they opt into the full DecentraFacebook edition but you don't want to see that crap, so you opt in to DecentraFacebook: Meme Free edition. You're still able to see friends 'direct posts'. No auto-play videos, no ads, etc.
Wouldn’t this mean a better, and thus more addicting and time wasting, social network?
Also, how could you really pull out data? If you put data out there and I make a copy of it and decide to keep it for all time how are you going to pull it back?
I think there would be competing ones out there. I don't think "better" necessarily means it wastes more time.
But sure, once you've given someone access to information, you can't make them forget it. Except through legislation (cough...GDPR...). You could revoke their access rights and they could no longer receive updates regarding your social graph.
