While not the same, but similar in some strong desires:
People run Nostr relays as people run Bitcoin nodes.
Discussion
No, there is no equivalency there because relays need to be actively managed and the volume and content on each one varies widely.
They're more like web servers.
I can run a bitcoin node. i don't think i can run a Nostr Relay. seems like it would require a level of keeping up the software, being aware of who's using it on a 24h basis, and not unplugging the thing from a wall.
i hardly even notice i'm running wss://mleku.nostr1.com it's just there, accepting notes from npubs i whitelisted and sending them to me
ok, i've visited that site. this is the one you pay to get a server on a cloud somewhere? so as long as I'm paying, it has my stuff on it?
is there an advantage to this other than storing your own notes?