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.
> Whoever is paying for the servers gets to call the shots
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.