Fediverse is well differentiated into many sites offering similar capabilities to their more well established commercial and proprietary counterpart, and as the time passes these federated alternatives quality is nearing practically the production level, apart from Mastodon and Lemmy which are the most known by now it is worth mentioning also PeerTube (Youtube), PixelFed (instagram), Misskey, Calckey and Pleroma (a mix between twitter and tumblr), HubZilla (facebook), FunkWhale(Bandcamp) and OwnCast (twitch).

Here some handy links:

https://joinfediverse.wiki/Main_Page

https://www.fediverse.to/

https://fediverse.party/

I use GoToSocial with Sempahore for my microblogging (alternative to Mastodon).

Also Owncast as an alternative to Twitch.

And then I watch tilvids.com and other Peertube instances for videos.

And of course Lemmy. :-D

Oh and then there's Funkwhale for audio.

It's all in different states of usability, depending on the communities involved.

Is/will there be a movie/TV equivalent of BookWyrm, something to track and discuss what you've been watching? A quick search tells me it's been discussed and seems like something people want but it doesn't look like it's been done yet, at least not as a dedicated service. Is that right?

Just a side note, ActivityPub protocol - the core engine that lets all of fediverse to talk to the rest of the fediverse is… 5 years old. Every feature imaginable is still to be implemented.