While this might be appreciated by a small number technical people it would just be confusing to the overwhelming majority. The cell, wifi, and battery indicators all provide information the user can affect by moving the device or plugging it in. An indicator would not provide any actionable information to the user. Also progress bars and time estimates for tasks are typically expected but in practice very difficult to make accurate. So you could not even accurately tell the user how long they need to wait for the device to finish it's background work

I don't see why they shouldn't include this when they include the info when it happens for a mac. When you get a new mac or it updates, you can see that spotlight is busy reindexing which explains the slowdown. I'm surprised there is not some one sentance explanation somewhere in the phone, like "processes will continue to update in the background and phone performance may be affected until this finishes" and boom, the OP article would have never been written.

"Background system processes running" wouldn't be obvious to non-technical users. It might even be distressing. If the process isn't something that can easily be explained to a regular user, I can see why Apple wouldn't try and communicate about it.

Though I could see maybe detecting that a user is a developer and showing a message only for those users

True, but it could be marketed a bit better: "Update finishing in the background"

People hate updates, it would make them more aware they are happening.

People deserve to know what their digital brains are doing on their behalf.

This is how Android shows it, and I think it is quite good because the phone feels slower while finishing the upgrade.

But unlike this (which is timed in hours) in Android it's done in a minute and then the notification is gone. Maybe Apple should start by doing the update in minutes first.

I find it really bizarre that it takes hours to run whatever background process iOS has after an upgrade, especially because in Android's case this is AFAIK rebuilding the Dalvik bytecode while iOS should use a compiled language (ObjectiveC/Swift).

Does someone knows what is iOS doing at the background?