Is New Game Plus unfulfilling?

Hey everybody I beat the base game and platted ghost last year. Coming back to it now and I'm wondering what's so good about new game plus?

We only receive ghost flowers for missions and exploration now? Which are only used for some dyes and I'm unsure what else? It doesn't give any incentive to explore the map again for me?

Why would I find all the haikus if I don't get a headband? Or the fox dens if I don't get the charm slots? I'm just not seeing the push here?

I just started so maybe you guys can correct me here but am I just wrong?