- performance is often better, especially on “out of core” (“streaming”, spill to disk data sizes). Polars has done a ton of work on their streaming engine but they’re still catching up

- you don’t need to use Python (but Pythonic wrappers like Ibis exist; disclaimer I worked on Ibis, you can find my blogs on performance comparisons easily there); CLI, WASM, etc. w/o Python

- governance: DuckDB as OSS is setup in a more sustainable way (DuckDB Labs + DuckDB Foundation). while there is a VC-backed company (MotherDuck), it doesn’t employ the primary developers/control the project in the same way the Polars company does

- overall just simplicity and focus. tends to break less, solely focused on single-node, easy to extend, etc. — not trying to do a cloud product, distributing computing, supporting GPU execution