Comment by david_allison

The Rust backend code is shared between all platforms (Desktop, Android, iOS and Web). This wasn't feasible with the Python code.

From an Android (AnkiDroid) perspective, it's allowed us to remove most of our code which was manually ported from the Python backend, with guaranteed 1:1 compatibility with upstream.

We've moved from being years behind upstream to being able to release in tandem with the Desktop app.

We also migrated to common screens written in Svelte, to reduce the maintenance burden of UI changes for screens with high churn (Deck Options being the primary example).