Good read.
Max Katz

iOS treats notifications as list items — similar to your emails where you have swipe actions. One possible solution to keep things the same way and still have the existing menu structure would be to add extended swipes to trigger the right-most action — which means swiping quickly and pulling the notification for an extended period would trigger the ‘clear’ action. The Android way of clearing a notification works because Android treats notifications as cards in an elevated plane. iOS notifications on the other hand lack that systemic reference to be implemented that way. Again, it is hard to understand what Apple’s goals are with ‘a notification’ since it does so many things; which is why it is even harder to suggest any direct solutions.