It’s called notification/alert/alarm fatigue and results in desensitization, with users often ignoring notifications entirely. This is terrible, as you’re then likely to ignore critical or important messages, tasks, and dates that you actually do care about (the whole reason notifications exist to begin with).

I imagine some people go the opposite way and anxiously work through each and every notification, elevating stress and sapping hours, energy, and productivity from their lives.

A lot more work needs to be done on giving users complete fine-grained control over notifications and level of severity by app; helping them take control, easily report devs for abuse, and adjust prefs ad-hoc from the notification view to aggressively silence everything that’s exploiting the privilege.