Others tell me if my server is getting swamped, forward important emails like renewing a cert, a deploy failed, bug in prod or something else that requires often immediate attention. Chat widgets from sites in production also go directly to Slack so I can reply quickly if needed. (Gmail, Sentry, Freshchat, Ploi etc, integrate them all and filter out what's critical).
Everything generally operates on a 15 min interval or so it's not noisy and I've pretty much tuned it to only receiving specific stuff I want to see. Having a central assistant like hub to go to is very useful and time saving.