Fediverse

You'll need to make a compromise between supporting the smaller instances or getting the wider audience.

Crossposting to both doesn't help the small instance, most people will keep replying on the larger one

Ironically, if Lemmy supported decentralization of communities in this way as PieFed now does, and as I guess Reddit did iirc, then you could post to a smaller community and people who were subscribed to such a multi-community feed would be able to see it.

However, there are many features of Lemmy that are even (far) more authoritian in nature than Reddit. Lacking both a modmail and hiding the account name of the mod who removed something of yours, plus not sending you any notification about the event, are three such examples, and there are many more where that came from.

On Lemmy, as on Reddit, a mod "owns" their community, and that's all there is to it - there is no decentralization inherent in the system, at least at the community level. Where the decentralization comes from is the ability to pack up and move elsewhere if needed. Or course, you would be able to take none of it with you, nor be able to leave a message at the old place that you had migrated. As you see, decentralization, while nowhere close to a "myth", is quite constrained - mainly I mean, that functionality is available to admins, more than mods. So nobody can tell you what to do with the communities on your personal machine, running the Lemmy software, which is open source.

Although PieFed allows for greater levels of decentralization in numerous ways, chiefly with the Topics and now the ability for users to create their own custom ones.

Although a caveat is that "cross-posts" - even those sharing identical URLs - between multiple communities are not collapsed in the listing of posts in a feed (yet, although as Rimu said it's a high priority to add that).