It absolutely isn't a Bitcoin version of Steemit.
The point of Steemit (and its fork Hive) is to have censorship resistance trough a blockchain, making content impossible to remove and guaranteeing consensus.

Nostr isn't that. It isn't Bitcoin-based or even blockchain-based. There is no consensus. Relays can remove content. Censorship resistance is achieved by using multiple relays that can host the same content.

They serve somewhat similar purposes but are entirely different. And Nostr can be integrated with any cryptocurrency, not just Bitcoin.