[Rikudou]

That sounds like a nice exercise for yourself, but I don't really see it competing with other privacy-focused or open source social media (which there are already many, you might want to drop the clickbaity "first-ever" bit from the title).

As already mentioned, you can provision a Mastodon server and either disable federation or even have it enabled and you instantly can see posts/comments from other servers as well.

[Ezpie]

I didn't know there already existed any. I will remove that first-ever part. Thanks for informing me.