StarGate on Nostr: please educate & correct me if I am wrong... I understood that Nostr doesn't have the ...

please educate & correct me if I am wrong...
I understood that Nostr doesn't have the algorithm features for interactions like other social media platforms.
So...
why my notes at the moment reachs no one (after being absent from #nostr for a few months)

a few months ago when I was more active my notes were getting much more interactions?

Is there an algorithm?
Is it the Relays?
what is it...