+1. GKE Autopilot and sticking to the core ~4 Kubernetes object kinds (Deplyoment, Service, Ingress), was a really easy way for us to get started with K8s (and in many cases can carry you a really long way).
Though easy to run, if there are multiple workloads of varying resource requirements, there will be a lots of wasted CPU and RAM, just because there are minimum CPU and CPU to RAM requirements.