Is there any benefit to host my own instance?
Sure.
I run my own instance at a cloud provider, and thus have monthly expenses I wouldn’t normally incur, if I were using a public instance.
The fun part is that you can run it on the same server as your mastodon is already running with no additional costs.
Oh, gotcha. I guess if using a personal local server, then the only recurring cost would be electricity.
Yes, there is electricity.
I think Internet connectivity could also be an issue, unless you have an ISP that’s friendly to you running a publicly accessible server on your Internet connection at home.
Could you run a local server on your desktop that you only turn on whenever as a client? I don’t really understand the Fediverse’s architecture yet, but as far as I saw instances being down are not a big problem beyond not being able to log in if it’s your home instance, and communities fracturing to separate discussions in other instances’ local federation caches that only get resynced when the thing comes back up.
What prevents me from running my own instance as a very heavy client? Discounting the public DNS + static globally routable IP part as those can be solved IMO.