IMO, that update failed, epically. Firstly, unless somebody was told there were an update and where to find it exactly, people would not know where to look for it and the OS would not notify them. I have had an iPad with automatic updates enabled plugged into a charger and connected to WiFi overnight and nothing happened. So what’s the point of these background security updates, when we need to proactively initiate them and then our devices would restart, which is exactly the same amount of effort as initiating the “regular” OS updates? 🤷🏻♂️