vCenter does not provide information for storage at cluster level but vRealize Operations does, including counters such as IOPS, throughput, and latency. The main reason why I do not look at storage at the cluster level when working with traditional arrays is that the cluster is a compute cluster, not a storage cluster, so the boundary a cluster provides for compute may not apply to storage. The other reason is that the data at this level, as for the ESXi host level, includes all the local datastores. They can impact the overall result, especially those that give an average of all the datastores. If you have a cluster with 10 nodes that share 5 datastores, you will have 15 datastores in the clusters. The 10 local datastores will skew the total result, masking important data such as the average latency.

For a view beyond disk and datastore, the datastore cluster is a much more useful object to look into.