Honestly the Fediverse is really better for connecting with strangers then locals. Not saying it can’t be done but yeah, everyone is probably still using Instagram, Snapchat, Facebook and etc. and to them they might see it as “no one is using the Fediverse” because not too many youtubers, or friends of theirs are actively using it.
You don’t need multiple accounts on each service to federate. So essentially if you wanted to communicate with a user, say from a Lemmy server on Mastodon you can do so. That’s federation.
Essentially the main things you are missing really from not joining another service is certain features, interface and a different focus and the like.
Right? so Peertube might have a completely different interface from Mastodon and Lemmy. And more of a specific focus on video related features.
edit: you would need a users handle, and then go to the service you use, like Mastodon and you can search for that user.
That’s something people could try experimenting with. I will see if I can find out what can be done with Lemmy, regarding Peertube and Mastodon. But I would asume that not all features from Masodon or Peertube would translate smoothly to Lemmy strictly because it’s a different software with a different focus.
Federation just means you can communicate with users from another server. Even if it’s a different ‘platform’ like Lemmy to Misskey, Mastodon to Peertube.