What do you mean? Your ‘zpool list’ is actionable: but the same number in a graph isn’t? If anything the report would show rate-of-change while an instant value would not.
Rates are a quick and easy way to see if something will become a problem soon (thus needs action) or if it can be ignored for awhile longer 
. Grafana makes that stuff easy.
Edit: Plus you can watch the soothing waves of garbage collection wash over your nodes: 
