Shadow and Bone question

In my opinion, no. What you summarized for Shadow and Bone pretty much sums it up. However, the second book is my favorite because a lot more happens with unexpected twists and turns. However, I will say that the build-up leading to the third book and the final battle is a disappointment.

I feel like yeah especially after reading the other duologies(they were written in a more mature setting)

In my opinion, both yes and no. I think in a basic sense the writing style feels intended for a younger audience than Bardugo's other books. Though I think any fantasy enjoyer would be able to read the story as well! (I would say SOC is better both in writing and plot dynamics)

I just finished the Shadow and Bone series, I thought it was okay, but i agree very young at times. I want to know what else happens in the Grishaverse though so I'm excited to read the Six of Crows duology and the King of Scars duology. Especially since people have told me it get better in Six of Crows.