Personally, I'd rather create a k8s deployment than an ECS task, but I can see your point. If all you want is an integrated with AWS experience, then it makes som sense that ECS is just simpler overall out of the box.

I don't think the delta to make k8s integrated is that much work with EKS, but ability to mutate the entire infrastructe if and when you do scale wins out for me. I think the complexity, most of which you can ignore, is worth the flexibility.

Either way, since k8s landed, AWS itself has started improving too.