Yeah, for sure. Anything trying to be a social network in a properly peer-to-peer fashion would have to be as simple to use (or simpler) than existing social networks, and / or offer some genuinely unique and desirable feature(s) in order to attract any serious critical mass of users.

Interestingly the original Napster was a pretty good social network! I really liked being able to browse through all of a user's shared files. We should bring something like that back.

"Anything trying to be a social network in a properly peer-to-peer fashion would have to be as simple to use..."

In practice this issue arise something like this: A decentralized service is launched it is so decentralized the user has to store their own private keys. Later a centralized solution is launched where the user does not have to go through the trouble of storing the private keys, everything is managed for them... everyone joins the centralized service.