Who owns it?

It's a completely free Nostr client. The data (notes, profiles and media) live on Nostr relays and are not hosted by Nostrich.

Okay. Then why did you choose to host these relays?

These are well known and established Nostr relays we’ve selected as defaults. You have full control over where your content is published. You can remove any of them or add your preferred relays including your own.

And how, pray tell, are relay operators and media hosters supposed to pay for hardware and electricity? Free to use in some ways, but not free.