1. Why would a user apply the extra policies?
It is a second line of defence after Istio autorization policies and it protects pods and services that are not protected by Istio
2. Effects they will have in the cluster
Please consult the name of and comments in each networkpolicy for further information.
3. We should achieve the same with AuthorizationPolicies
But there are components, e.g. Katib that are not secured by istio