If you are going to do that, you could stick with Jupyter + nbconvert.

I rarely use notebooks directly anymore unless I require the output to be stored. Do most everything in VSCode with interactive .py files. Gets you the same notebook-y experience + all of the Python tooling.

marimo notebooks are actually DAGs as cells, reusable out-of-the-box in three diffferent ways: as interactive computing notebooks in a reactive environment with no hidden state, as Python scripts, as data apps. So Jupyter + nbconvert (or perhaps you meant jupytext) is not a replacement for marimo.