Notifications vs. badges
Something I’ve noticed while working in the office:
Push notifications (on your computer or otherwise) are a near constant distraction. That banner across the screen, the text, the urge to read it—it’s a diversion that forces you to abruptly and constantly change your focus.
Repeat it three dozen times per work day, and it’s easy to see that a significant chunk of time gets wasted.
Badges, on the other hand, keep your mind on the task at hand. It communicates that there is something to read, without forcing you to lose focus reading it.
Badges give you the freedom to continue to work with minimal disruption. Abrupt announcements (of any kind) don't.