It's better than the #[x] stuff. This is more flexible as you can decide to add tags or not, or embed relays or not in the bech32, and for raw viewing of an event (or very nascent clients) it's easier as they can just display the raw NIP-19 code and that kinda works. Also it's simpler for clients to format/render notes that have raw npubs pasted that were not caught by autocompleters and turned into tags as the text was typed.