At its core, Kubernetes is a controller manager. It's true that most Kubernetes systems include a lot of the Hashicorp equivalents but you could in theory remove the controllers and associated CRDs. Kubernetes has gradually moved to what I think is a relatively sensible set of defaults which you can get in different flavors (k0s, k3s, microkube, kubespray, etc.)
The comment about development and packaging tools can indeed present a problem. I tend to favor Helm for applications that need to be deployed more than once and Kustomize to differentiate between environments but I've definitely seen what I would consider horror stories. Even if you add a bit of GitOps, it's not too hard to understand. The horror stories seem to occur when teams try to map their previous workflows directly to k8s. Many times the worst k8s development workflows are created to enable teams that had broken workflows without k8s.
The comment about development and packaging tools can indeed present a problem. I tend to favor Helm for applications that need to be deployed more than once and Kustomize to differentiate between environments but I've definitely seen what I would consider horror stories. Even if you add a bit of GitOps, it's not too hard to understand. The horror stories seem to occur when teams try to map their previous workflows directly to k8s. Many times the worst k8s development workflows are created to enable teams that had broken workflows without k8s.