We faced increasing complexity managing lengthy crontabs with scheduling being an issue, this required carefully planning timing due to resource constraints, usage patterns, and especially custom code needed for retry logic. In the last case, having to verify success of previous jobs and/or steps prior to running the next. Furthermore, time to results is important, but we were increasingly relying on buffers for processing, where things were effectively sitting idle and not processing, waiting for the next stage.
Relying on community built and existing hooks and operators to the majority of cloud services we use has allowed us to focus on business outcomes.
Airflow helps us manage many of our pain-points, letting us benefit from the overall ecosystem and community. We are able to reduce time-to-end delivery of data products by being event-driven in our processing flows (in our first usage, for example, we were able to take out over 2 hours - on average - of various waiting between stages). Furthermore, we are able to arrive at and iterate on products quicker as a result of not needing as much custom or roll-our-own solutions. For Our code base is smaller and simpler, it is easier to follow, and to a large extent our DAGs serve as sufficient documentation for new contributors to understand what is going on.