@kemal Ahh.. I see.
But, how do other networks do it then? Because then in the case of Nostr (I don't know this one, I'm just going by the info you gave me), if it is yes-ish decentralized according to your idea of decentralization, it means that your data would be stored somewhere on a master server of sorts? Which would mean that it wouldn't be decentralized after all. (Guess that's why the yes-ish..)
I think what you think of as decentralized is very hard to achieve. Maybe for a Tor-network or sometihng?