Good read. I think notifications are an after-thought in iOS in general. Android executes notifications better.
When you clear notification by swiping left — why do you need to click ‘clear’? Why not clear the notification just by swiping left (like Android)?
You have to 3D touch on notifications to interact with them and also clear them all. It’s difficult to do a 3D touch when holding the phone in one hand. A (menu) action would be simpler.