My rule to use Kubernetes is only if my containers exceed the extra containers I need to make Kubernetes work, including but not limited to:

  - kube-state-metrics
  - Coredns
  - Prometheus
  - Alert manager
  - Node Exporter
  - Spot instance termination handler
  - Karpenter/cluster-autoscaler
  - Event Exporter
  - Kubernetes Dashboard 
  - Ingress
  - Cert-Manager
  - Custom CNI?
  - Istio (not always)
  - ArgoCD (not always)

Even if they are configured with fractional CPU (which mostly causes stupid throttling issues) they still are headachaes to maintain. I used to run 4000 pods in a single cluster, using Kubernetes was great. Otherwise, nowadays I'd just go with Fargate/Cloudrun/Fly.io etc.