Some people have mentioned some decentralized services like diaspora* and Minds. I've looked at diaspora* in the past as well as another decentralized service called Mastodon. I think decentralization is a critical component for next-generation services (currency & communication). To that end I would also suggest having a look at what Tim Berners-Lee is currently up to with development company Inrupt Inc. & the framework for decentralized web applications they call SOLID. Right now they are targeting "the highly technical".
Re: Drupal 8 features, I would also note that Drupal has some excellent caching mechanisms which work well when paired with reverse-proxy caching and/or CDNs (essential for scalability).