I have spent a lot of time in Jupyter notebooks for experimentation and research in a past life, and marimo's reactivity, built-in affordances for working with data (table viewer, database connections, and other interactive elements), lazy execution, and persistent caching make me far more productive when working with data, regardless of whether I am making an app-like thing.
But as the original developer of marimo I am obviously biased :) Thanks for using marimo!