Unless your relay collects that information for you :)

Sue you can. Sometimes that "somehow" is possible, given the laws of physics, what constitutes a reasonable infrastructure spend, what the chances of coordinating or limiting the parties involved are. And sometimes it is not. Also on nostr there are many things that are possible theoretically but impossible sociologically. Take NIP-04 depreciation. In theory once everyone agreed it was unsafe (which happened years ago) it could have disappeared overnight, for the safety of all. But sociologically that's an impossible outcome, and so it's still with us now. Gets a bit old hearing nostr can do this, or nostr can do that, when the things being suggested are sociologically impossible. And no, adding the "if we just get everyone to agree" caveat doesn't get us out of this.