Scale, interactivity, and durability are certainly part of this discussion. You can use Cadence/Temporal for purposes you just really couldn't use Airflow for. For instance, you could implement this entire actor-based auction example from Akka with Cadence/Temporal https://doc.akka.io/docs/akka-enhancements/current/persisten... There is absolutely no way you could do that with Airflow.
To understand why Cadence is so useful, you have to go a bit beyond the traditional ETL scheduling usages IMO.