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
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
After having checked out Plex, Jellyfin and Emby I've decided the latter was still my favorite. Jellyfin just isn't there yet, lack of built in image-scrubbers, intro-outro-detection and quality clients just makes it inconvenient for me. Plex's external authentication makes it a no go for me.
Emby is the only one that's focused on what it tries to achieve and delivers. Also the support team is super helpful and pushes out fixes in a pretty good time. Not FOSS though
Scraping sites to gain information and spinning a web of interaction and activity are 2 different things. If your fine with Meta having this data easily available that's on you. No one stops you from signing up with their services but most people here want to distance themselves from huge corporations and their shenanigans
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"