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.