I think the power of the fediverse is in there being more, smaller servers. It makes moderation easier and should scale better. It prevents one person or group getting control over the whole network.

The advantages of having your own server are about having control over the instance. I can choose which servers I do it don't federate with. Also I know my data isn't being misused. Plus, to be honest, I've got lots of experience running this sort of thing and I like the idea of offering the benefits of that to the community.

In my case I decided to base my Mastodon server and Lemmy server on my local area. I like the idea that the local timelines and local posts would be relevant for that geographic community.

Running your own server isn't for everyone though. It takes a certain amount of commitment and money. I get some donations - which are lovely - but I'm still basically funding it out of my own pocket.