What you've listed for k3s is mostly included in k0s. I wouldnt go far to say k0s isnt convenient.
* A helm controller is included in k0s
* Etcd is bundled and bootstrapped automatically which I perfer because I dont want the overhead of the translation that Kine does. Although Kine is available for a non-etcd datastore if that is preferred.
* Upgrade controller is included (autopilot).
* They have a local storage provider based on OpenEBS.
* Ingress is missing, but due to the built in helm controller that can be boot strapped upon cluster initialisation.
Overall, together with k0sctl and its declarative configuration it is easier to deploy k0s than it was k3s.
Kine (https://github.com/k3s-io/kine) is a shim or an external process (when not k3s) that translates the etcd api to enable compatibility with a database or alternative data store.
Kubernetes natively talks etcd, so this translation is what enables its usage with sqlite or another database, but it incurs an overhead.
I don't have specific numbers unfortunately since it was years ago I benchmarked Kine against etcd. But I had a better results with etcd both in cluster and single node.
* A helm controller is included in k0s
* Etcd is bundled and bootstrapped automatically which I perfer because I dont want the overhead of the translation that Kine does. Although Kine is available for a non-etcd datastore if that is preferred.
* Upgrade controller is included (autopilot).
* They have a local storage provider based on OpenEBS.
* Ingress is missing, but due to the built in helm controller that can be boot strapped upon cluster initialisation.
Overall, together with k0sctl and its declarative configuration it is easier to deploy k0s than it was k3s.