I like the idea with Lemmy/kbin and the fediverse but theres something I dont understand perhaps.
If in the future Lemmy is very popular and someone wants to add their own server and federate with everyone then from that moment that new instance will get all new comments, posts, etc. from all other instances its federated with and must save them in its db. This means if Lemmy gets popular forget about little guys helping out spread the “load” because every intance still must take and save all new data. Thats a lot of processing power and storage. How can this work? I see in the future only a few instances will survive.
If somehow each instance was a node and only took care of its posts and comments and forward them to others upon request I can understand scaling but this is not how it works AFAIK. Another way would be with consensus algorithms where a node saves more thsn its own data but still not all.
This is literally how the entire internet works. You are describing CDNs.
Additionally, from the perspective of the protocol (ActivityPub), there is no such difference which you are describing.
Communities are “users” which can be “followed” (subsribed to) by other “real” users. Essentially they are bot users that other users can post content through, to its followers. There is nothing different in how the threadiverse functions compared to the fediverse at large. Only its format.