Though to be fair: simple use cases are not hard in kubernetes either. Writting a manifest for deployments, services and ingress rules is not that complicated. Nowadays setting up a kubernetes cluster with Rancher or kubeadm is slightly more complicated then initating a swarm and joining swarm members to the cluster. Usualy those things outside the scope of what swarm offers are getting more complicated.
What you wrote is undeniable if you realy want to leverage all bits and pieces of the Kubernetes eco system. It is true that there is an awful lot to learn, which permanently needs to be updated because changes are very fast paced.