Need for skip crds flag for base chart using ArgoCD (helm) during istio upgrade

I am using istio in my K8s cluster using ArgoCD (helm installation) and I was wondering why are the CRD’s applied separately according to the istio base installation guide.

I tried to install istio (and then upgraded) without this additional step and everything seems to be working fine. Is there something I should be worried about?

Thanks in advance.