We use it for simple use-cases and experimentation, especially because it works so well with various data formats and polars. Personally, I prefer to maintain proper SQL queries against duckdb including re-usable views, and then use polars for the remaining fiddling/exploration.
In combination with sqlalchemy, it is trivial to lift an app to other OLAP systems.
In combination with sqlalchemy, it is trivial to lift an app to other OLAP systems.