Besides the "Save for later" & co, just mute all the channels that aren't essential and leave the obsolete ones. If someone wants to raise issues from marginal

Besides the "Save for later" & co, just mute all the channels that aren't essential and leave the obsolete ones. If someone wants to raise issues from marginal sources, let them go through the friction of messaging in the main channel or DMing. You don't need to react to everything.