If you choose a) you don't really get to avoid b), since something still has to bootstrap your Kubernetes nodes themselves. So it's more a question whether you'd rather write a Kubernetes manifest or a Salt/Ansible config; and with the complexity and limitations of a lot of storage operators, and no real "orchestration" benefit once you have pinned deployments to particular nodes anyway, sometimes it's the latter.

The main force that's pushing us to move our storage into K8s isn't simplifying our node configuration, but to keep parity between our prod and more dynamic staging environments. For the latter k8s storage operators are great because we don't generally care about data durability or performance.