Yeah. Its an interesting point about decentralized services. They're just small servers. Larger servers run by corporations are more profitable, hence they dominated the internet. But one question about email - wasn't it an end to end service with people sending email directly from their computers without needing a server (initially)? Apparently servers were needed later to authenticate users and prevent abuse.

However on social networks like GNU Social, diaspora, etc I agree - they're just small servers. Right now tough to setup and maintain. In the future probably someone could make it as easy as click and install.
Also concerns about privacy apply here - say if you have a server and your friends are in it, what would prevent you from spying on them and violating their privacy? (a question on this regard was asked by a friend).

But is end to end social networking possible?

Fully decentralized serverless systems are undoubtedly superior in many ways to federated server based systems. But, I don't think serverless systems are necessarily immune to appropriation and centralization by big corporations.

For example, email did start out as a serverless system, but was later absorbed into big monopolies and mostly centralized. As a result, email has become one of the most difficult things to self-host. Some reasons given for this, such as spam, are legitimate, but IMO were blown greatly out of proportion. Many anti-spam measures are sledgehammers instead of being scalpels.

BitTorrent is almost serverless. Yet, these days, with data-limited and firewalled mobile connections, it's not too easy to run. As a result, you have recentralization of torrents in seedboxes. Or, you have people completely abandoning torrents in favor of sites like YouTube.

Maybe, some level of user awareness is indispensable to avoid falling back into the trap of centralization.