Slack is especially bad, as it has no filters whatsoever. Looking over at that tab in my browser, it always has an asterisk next to the icon, and usually an exclamation point telling me about a Very Important Direct Message that is invariably somebody in another timezone saying "Good morning @channel!"
It's the sort of thing that deserves checking a few times a day. Why you would configure it to pop up desktop notifications or make noises on you phone is beyond me.
But you're right. I have resorted to checking Slack just few times per day as well rather than being online constantly.