Keys are compact and consistent across records (e.g., 'draft', 'done', 'cancelled'), which makes them easier to query and process in the backend.

Values (display text) can be longer, localized/translated into different languages, or dynamic, which would make database queries less efficient if stored directly.

The localization impact is significant, if someone in Spain marked a Sales Order as "Hecho" then it would cause problems for someone in the United States looking for Sales Orders marked as "Done".