The vSphere Container Storage plugin supports shared NFS, vNFS, and vSAN. You need to provision your storage options in vCenter prior to creating a CAPI image in DKP for use with vSphere.
DKP has integrated the CSI 2.x driver used in vSphere. When creating your DKP cluster, DKP uses whatever configuration you provide for the Datastore name. vSAN is not required. Using NFS can reduce the amount of tagging and permission granting required to configure your cluster.