The important difference with k8s from my experience is that from the very early days it modeled a common IPC for any future interfaces, even if TPR/CRD tools some time to hash out. This means that any extra service can be simply added and then used with same general approach as all other resources.

This means you get to build upon what you already have, instead of doing everything from scratch again because your new infrastructure-layer service needs to integrate with 5 different APIs that have slightly different structure.