Each peer is a server That’s not true, you can be a peer in the network without posting or seeding anything to the network.

peer that created the “sub” have control to be able to moderate things If you create your own community, you will be able to moderate it, yes. Why would people create communities when it can’t be moderated?

With Plebbit there’s no global admins like Reddit, so you fully own your community and nobody can take it away from you.

You have to maintain your peer always online, because it’s a server If the community node is down, but other peers in the network are online and providing the community’s data, then people will still be able to read and navigate the community in read-only mode. They can’t publish new votes/comments/edits to it, because all updates has to come from the community node.

Traffic happens over IPFS, which is sloooooow Not true, try the desktop app of Seedit and you will see for yourself.