Earlier quoted context omitted.
Is it decentralized? While definitely better UX to remain centralized, I think Reddit is clearly showing why that's a problem.
Any problem happening on reddit could also happen on a "decentralized" platform. Whoever is paying for the servers gets to call the shots. All federated options should be automatically eliminated from contention if we're taking it seriously as a reddit replacement.
But if everyone can run a server; if I can run my own server just for me to only fetch the stuff I'm following, then I'm not beholden to some unknown or commercial hosting entity.