Some basics you should read about if you're into decentralization:

BitTorrent - Wikipedia

Bitcoin - Wikipedia

Peer-to-peer - Wikipedia

Here is a quote from

Radicle Seeder Guide

Sovereign code infrastructure.

"While a peer-to-peer network without seed nodes is feasible, it is impractical. This is because regular “user” nodes go online and offline all the time, so finding a user from which to download a certain piece of content can be challenging, or even impossible if all users with that content are offline. Therefore, a healthy peer-to-peer network necessitates at least some highly available nodes that participate in the network like regular peers, but seldom go offline. These are called seed nodes."

Btw, I'll apologize for my condescension if you apologize for trying to conflate "I made a project that uses git and git has always been decentralized" with "I made a decentralized github alternative"

I'm enjoying the irony that you are complaining that nostr isn't decentralised enough via the primal caching service