I have got some feedback that the Arrow Python API documentation is a bit confusing as the ToC/Menu is only really visible on the front page. People get confused by the top header. As we are already diverging from the main homepage as this was migrated to a newer bootstrap version anyway, I suggest to change the documentation theme.
As a best practice, I would switch back to the sphinx_rtd_theme as this provides a UX people are used to and happy with. We can customize it if needed later as e.g. dask did: https://github.com/dask/dask-sphinx-theme