Implying that Airflow is a simple mixture of a few ingredients is selling it quite short. There are a lot of knobs and switches in Airflow (i.e. features) that have been built and battle-tested over a lot of users. It has quite a lot of dependencies across the scheduler, webserver, cli, and worker modes. And there is a lot of new development going into Airflow in recent months (new API, DAG serialization, making the scheduler HA).