author here - you're right that the average user doesn't care about decentralization as a first order benefit. people typically use social networks to be entertained / informed or to increase their status. we've been building a new, decentralized social network and we've learned this first hand.
but if you've figured out a new social network, building it in a decentralized manner today might give you very strong second order benefits. and its now possible to do this in a way that doesn't compromise the user experience.
I also was reading your post with the mindset "how to regulate social networks". I strongly believe that all big organizations need regulation. It is not easy to regulate social networks, but heck maybe it wasn't easy to regulate telephony or energy.
but if you've figured out a new social network, building it in a decentralized manner today might give you very strong second order benefits. and its now possible to do this in a way that doesn't compromise the user experience.