Kubernetes
Useful if you sell cloud-agnostic software. Otherwise, use your cloud natively.
Kubernetes makes sense if you're selling software that customers deploy on their own infrastructure across multiple cloud providers. For everyone else, it's unnecessary complexity.
AWS ECS/Fargate gives you container orchestration without managing control planes, etcd clusters, or node pools. The operational overhead of Kubernetes — upgrades, networking policies, RBAC, ingress controllers — is a full-time job. We've run production workloads on Fargate for years and the total cost of ownership is a fraction of what Kubernetes demands.
If your application runs on a single cloud provider, use that provider's native container service. The abstraction Kubernetes provides costs more than the portability it promises.