I have a new Lemmy server (lemmy.todayyoutomorrow.me) and I've noticed only communities I subscribe to show up.
The idea was to have my own local instance but I don't see how I can find new communities without using another instance first and finding those communities there and then manually adding them to mine. I have found the following two github projects:
Use a site like browse.feddit.de to find communities you want to join and join them. Every instance only "has" their local communities plus whatever remote communities the users of the instance join. With more users it is more likely someone else has subscribed to something you are interested in, but someone on e.g. lemmy.world had to be the first user there to search and subscribe to any community that isn't based on that instance.
What's interesting about this is that there really isn't an r/All. All@lemmy.world will be different from All@beehaw.org, will be different from All@lemmy.ml, and will be VERY different from All@lemmynsfw.com
Yeah, as someone who used Mastodon back in the day this wasn't surprising, as they sorta highlighted your vs local vs public timeline, but I can totally see how it could be confusing expecting Lemmy to just be a "reddit clone". And TBF it is a reddit clone of sorts if you disable federation, "All" is everything your instance can possibly access, but then you lose out on what IMO is the killer feature.
There is probably a way you could spider instances and scrape content to get an "All" of sorts...
Yeah, this is kind of disappointing. There's no consistent experience. What I see may be very different from what you see and while that's in itself is not necessarily bad, it makes it hard to discover communities.
I guess it's the price we pay for decentralization and I'm okay with that.