Yep, Inngest does something similar — it can layer over any event stream (NATS, Kafka, GCP Pub/Sub, SQS/SNS, etc.) in order to subscribe to events & trigger functions. We provision that for so you don't need to manage anything when you sign up to us, though it's definitely flexible :)

That said you still need a state store and queue capable of future publishing internally to make things work; if you want to run anything durably, you're going to need to manage state. That's still flexible but a little less so — you need to choose both a queue and a backing state store to make that work.