Nostr is properly decentralized with cryptographic identities, not just federated (aka. centralized with extra steps). Servers are just dumb relays and interchangable, they have no power over their users. It’s also a really simple protocol.

LBRY is decentralized in theory too, but a whole crypto currency intermingled in it, making it a lot more complicated and harder to understand. The company being LBRY also get killed due said crypto currency.

That said, this is just Nostr itself, for actual video hosting you need some stuff on top. No idea how exactly this is handled here.