In the typical web marketing infrastructure, a company signs up for an email account for private messages, Twitter/X account for microblogging, YouTube account for video sharing, and Reddit for forum discussion.
With the Fediverse/ActivityPub model, currently a typical user might register a PeerTube account for video sharing, Mastodon for microblogging, and Lemmy for forum discussion. But the data under all those is the same infrastructure, right?
Facebook as a mature software platform has areas of its app for private messaging, microblogging, and video-specific content, all using one user account.
Is it likely that Fediverse apps will evolve toward a similar structure, where a person or company would only need one account and could push out content of all types there, and interact with others’ content with one account?
No, you’re not quite understanding what ActivityPub is. The data under all the fediverse services is not the same infrastructure at all. The communication between those various services just uses the same language (ActivityPub). Those various services can interpret and store (or ignore) ActivityPub messages any way they want. Service instances add another layer to the whole thing as well.
In order for an “everything app” to be successful (if you buy the argument that it feasibly can be), it would have to be a centralized service. Decentralization, by its very nature, encourages the opposite of that – want to make some niche service because existing services don’t satisfy some fringe need you have, but still want to interact with others on other platforms? You can do that with the fediverse. But that also means your new service isn’t part of an “everything app”… it just can potentially talk to one that might exist.