among other things, I miss Autopilot and generally the extensive machinery to help with massive capacity planning.

Think of Autopilot as an automation that tweaks a pod's request/limits according to what it actually needs in order to reduce waste and thus improve cluster utilization.

(I _think_ this no longer qualifies as secret after https://github.com/kubernetes/kubernetes/issues/44095)

That said, k8s is quite extensible and it would definitely be possible to add such a component as a controller.