As I understand it, there's a huge downside to federated software in the requirement to be Always Online.
Lots of people have slow internet connections, or no connection at all, preventing them from accessing their software.
Everyone should be able to use the programs/apps they have without regard to whether they are online or can get online.
What federated software would actually make sense to work offline, though? Everything I've seen is literally internet tools like social media (forums, blogs, chats, etc). None of those things would work offline. Is there, like, a federated paint or word processing app or something?
This isn’t really specific to federated software. The client can go offline but the server can’t. Same applies to all centralized services. The only place this really applies is for decentralized (as in, no central points) systems, and those tend to have a lot of special sauce to make other people being offline less painful