I know interoperability between email providers is often used to make the concept of federation more aproachable but other than that they are totally different systems.
Your sent emails aren’t published and not everyone with an email server can track your activity. Unlike lemmy if it connects to threads
How so many people seem to brush this off is beyond me. As far as I’m concerned the purpose of federated, decentralized services is being in charge of who to trust and huge corporations not controlling or monitoring every part of your online activity.
Obviously as soon as Meta starts dealing with ActivityPub and Fediverse, the overwhelming majority of users will flock to their servers. They will be more userfriendly and responsive. In effect they will also hold the overwhelming majority of content and data. Just a matter of time till most of the other instances will become obsolete, due to bandwith regulations or smth similar,
The fediverse will be rebranded as the “Threadiverse”
It’s a “flaw” of the fediverse in general not about private data. As soon as two instances are federated and users interact with eachother, information like posts, comments, votes etc are shared