tl;dr we use it for a similar set of tasks that one would use Airflow for.
Unlike Airflow, this lends itself to microbatching and streaming. Plus a bunch of housekeeping items ticked off that Airflow never got around to. With a bit of devops engineering time, you can have perfect manage the size of your worker cluster on k8s and scale it up/down with ingest demand, etc.
I'll say one thing though. The Perfect website used to be a lot more technical and explicit about what it is and isn't. Now it's mostly sales gobbledegook. Maybe not a good sign. I've seen this happen before with dremio.
Do you run dask on k8s ? I have been concerned that dask does not leverage kubernetes HPA for autoscaling...but instead chooses to run an external scheduler.
Spark stacks inevitably end up with PySpark though. It's rework for people who already committed to Spark, sure. And for bigger projects that committed to Spark this change isn't justifiable. But for a greenfield project, choosing Spark is just silly today.