Why we need to write the apiGroup key in this definition again and again , if it is the same every time:

kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
 name: web-rw-deployment
 namespace: some-web-app-ns
subjects:
- kind: User
 name: "joesmith@example.com"
 apiGroup: rbac.authorization.k8s.io
- kind: Group
 name: "webdevs"
 apiGroup: rbac.authorization.k8s.io
roleRef:
 kind: Role
 name: web-rw-deployment
 apiGroup: rbac.authorization.k8s.io

• this looks so redudant , that is repeating for everything
• if we need to write it , what are the other values
• if there are not other values for the field RBAC apiGroup , then k8s should assume that value automatically apiGroup: rbac.authorization.k8s.io

this makes the yaml too redundant , is there any way to work around this. can we just skip this key? OR can we declare this somewhere globally.