Agreed, watching dashboards is no substitute for alerting. However, one of the motivators for doing this is to reduce pressure on the metric backend. It's common to have Grafana reports refresh at 5s intervals, which if you have sub-second data, means that you request the same (potentially tens of thousands of) points over and over again. Some have worked around this by adding a caching layer (see https://github.com/Comcast/trickster), but streaming feels more elegant :)