[ceeplusplus]

I think many of these are inherently poweruser features though. Most non tech-savvy people will rarely have to turn off their phone or clear their open apps (really if the memory eviction system is good this shouldn't even be a concern).

Some of the other stuff you mentioned is discoverable in my opinion. Swiping down from home gives you a search bar. Notifications being accessible by swiping down from the left is admittedly not as good as swiping down from the top bar in the older iPhones, but I think still more discoverable than the Windows notification system that requires you to click a button.

[nfw2]

Turning off the phone is useful if you are low on power and don't have a way to charge. I do this sometimes when traveling or in the city.

When I go through open apps, it is usually to get back to something I was doing, rather than to clear it. Finding what you were just looking at 2 seconds ago shouldn't be considered a power user feature.

[layer8]

From time to time you need to reboot the phone to get some nonworking app or system function unstuck. I regularly have to guide family members to reboot their phone or tablet, and have to google each time which button combination has to be pressed on the particular iPhone or iPad model.