I work writing analytics and monitoring for industrial equipment. We have hundreds of sensors sending back realtime data.
There was a period of time where people were writing alerts for the sake of it (i.e we have this sensor, when should we alert on it).
Nowadays we're strictly failure mode driven, this has meant lots of sensors aren't used in the analytics. They are however available to the experts to plot them for a more holistic view if required.
We went through the same switch. Half our alerts had been firing for a while and nobody ever acted on them.