[txcwpalpha]

I'm still not seeing the difference. As pointed out, what you linked is for ECS. That has nothing to do with Kubernetes, so I'm not sure why you're comparing the things on that page to kubectl commands on GKE or Azure. Of course you cannot use kubectl on ECS, because ECS has nothing to do with kube.

When you are using actual EKS (with or without Fargate), you certainly can use standardized kubectl commands.

The only "proprietary" things I see in your link is the specific AWS CLI commands used to set up the cluster before you can use kubectl, but both Azure and GCP require using the Azure CLI and gcloud CLI for cluster deployment, too. There's also setting up AWS-specific security groups and IAM roles, but you have to do those same things on GCP or Azure, too, and both of those have their own "proprietary" ways of setting up networking and security, so I don't see the differentiating factor.