Slack is the most counterproductive tool ever for me. I cant turn it off or ignore it because my manager will be upset. Im spammed constantly with notifications

Slack is the most counterproductive tool ever for me. I cant turn it off or ignore it because my manager will be upset. Im spammed constantly with notifications from all the channels Im supposed to monitor and most the traffic isnpointless chatter. I really wonder if anyone at my company is even getting any work done.