When the upstream istio is removed from cluster it leaves the cluster in broken state.
New pods fail to start with:
(combined from similar events): Failed create pod sandbox: rpc error: code = Unknown desc = failed to create pod network sandbox k8s_registry-puller-89bd55495-8qc6s_registry-puller_b0cf5e01-383d-11ea-93d2-fa163ee5acb3_0(d93218e9cc51c4a6ed1a49829e9983d01ba0071bea5bb55dfadbac9345aa3996): Multus: Err adding pod to network "k8s-pod-network": Multus: error in invoke Conflist add - "k8s-pod-network": error in getting result from AddNetworkList: failed to find plugin "istio-cni" in path [/var/lib/cni/bin /opt/multus/bin]