Dataframes are popular among people who are trying to use the data in a way that they don't intend to do anything more with the processed data after they've reported their findings.
I've been testing polars and duckdb recently.. Polars is an excellent dataframe package.. extremely memory efficient and fast. I've experienced some issues with a hive-partitioning of a large S3 dataset which DuckDB doesn't have. I've scanned multi-TB S3 parquet datasets with DuckDB on my m1 laptop executing some really hairy SQL (stuff I didn't think it could handle).. window functions, joins to other parquet datasets just as large, etc. Very impressive software.
I haven't done the same types of things in Polars yet (simple selects).
Dataframes are popular among people who are trying to use the data in a way that they don't intend to do anything more with the processed data after they've reported their findings.