I think you comically underestimate what Kubernetes provides.
Autoscaling groups give you instances, but Kubernetes automatically and transparently distributes all your running services, jobs, and other workloads across all those instances.
A big part of what kubernetes provides is a standard interface. When your infra guy gets hit by a bus, someone else (like a contractor) can plug in blindly and at least grasp the system in a day or two.
