Basically just the hastle of maintaining and hosting it. My ideal situation would be an instance with a few people, where we can share some of the burden, and perhaps cost. But maybe that has its own headaches when there is a falling out etc.

All very good points. I wouldn't mind sharing the costs and burden with some folks, but I'm pretty happy just maintaining it myself. Again, for me, it's something I enjoy doing.

There are also other drawbacks with your own Mastodon instance in terms of discovering new people, as a lot of those tools are geared towards the server scope, and Mastodon prohibits a full index search.

I never really had that problem, but then I started out on other Mastodon instances and just migrated my account around until I ended up on my own personal instance. I also participate in several relays, which helps a lot. In the end, I've also spent time looking at the public feeds on other servers and browsing their profiles to find people. Another thing I did was participate in conversations, which was a good way to get mutual followers.

With that being said, I don't follow a ton of people either. I read my entire timeline, chronologically, so I keep it pretty tailored. I disable boosts and mute/unfollow people often.

I actually don’t know what the Lemmy policy is on indexing, but a way to search the entire Fediverse (or at least large parts of it) would help tremendously in popularizing it, I think. I understand why indexing would be blocked, but that seems a lot like security by obscurity to me, which I don’t think works very well.

Lemmy indexes everything on the server, as far as I know, which means you should be able to find local content and content federated to the instance.