As someone who hosts a small instance, nothing massive....

Honestly, nothing.

The only benefit I get- is full control over weather my instance is up or two. I know for absolute certain that my instance isn't going to randomly shutdown, and not come back online.

I also have the benefit of having a lot of control over how fast my instance is, and performance optimizations as needed to make it perform as I would like. As such, for me, the performance is outstanding.

With that said,

Basically everything else is downsides.

Having to proactively moderate content originating from your server, is a drag. The moderation tools in Lemmy are absolute dog-shit. Your only option here is to use either 3rd party tools (lemmy-helper), or to just run database queries.

PictRS just keeps growing and growing. pictures gets synced to every instance, and those take up room. Lots of room. PictRS has even less moderation tools then lemmy. If you want to make sure your user aren't uploading illicit/illegal content, is a major pain in the ass. My solution was to run a few scripts to fetch all of the content, and just run it through some AI scanning software to attempt to detect bad content. But, still, a pain in the ass.

Those attacks you read about here on lemmy world. Those happen to our smaller instances too. Every time you hear @ruud@lemmy.world doing an update here- we are also working on plans for updating the instance. Granted- my small user base makes these upgrades much easier and faster. But- we will have to do these updates. (At least on the plus side, my instances isn't constantly under a DOS attack, due to a disgruntled member, or due to a pissed off instance which was defederated)

And, lastly, one downside of lemmy- things don't really go away or get cleaned up. Your database and storage will continue to grow and grow, and grow. Again, to restate, There are basically no moderation or administration tools included with lemmy. You can see reports. You can ban users. And, you can delete posts. Thats about it.

There isn't an easy way to even list users, comments, posts, or activity happening on your instances.... through lemmy itself.

On top of those other issues, lemmy is very chatty, network wise.

Here are the incoming stats, from my "small" instance.

In terms of outgoing, it's very chatty there too. You will find all sorts of weird and random outbound DNS records.

tldr; Its prob not worth hosting your own instance, unless you just really like playing around with infrastructure, networking, databases, and digging through application issues.

Personally though- I enjoy the challenge, and that is one reason I keep doing it.