For the longest time, you couldn't control any of the notifications coming on your phone from Android itself. Things like apps running in the background or using battery, networks alerts or your VPN status had to stay there front and center in your notifications until you dismissed them. Then with Oreo's notification channels, you could at least lower the importance of a notification so it didn't take precious space in your drop-down. Oreo 8.1 also introduced one neat change: you could disable notifications for apps running in the background, but that was the only one to be turned off completely.