Funny, I know a decent amount about k8s these days, but I've never really used AWS. I think there's a lot of systems that try to solve the same problems: "define these services, keep them running, here's how to check if they're down, here's how to restart them, keep resource usage to this level." Systemd, kubernetes, and individual cloud providers all have their own way to describe these.

One of the upsides of k8s is that it gives you a general, platform-agnostic way to describe this, on AWS or GCP or self-hosted or whatever. The downside is that it's more flexible and therefore more abstract than any particular provider. The upside is that you only have to learn one set of concepts (in theory).