How can I use Reachability on iPhone X and later?

The iPhone X does not have a home button thanks to its edge-to-edge Super Retina display. So without a double-tap on the home button, how do I use Reachability?

iOS 11 home screen

Reachability can make one-handed use of the iPhone easier by bringing the top half of the display down to the middle of the screen. To use Reachability on the iPhone X and later:

  1. Enable Reachability under Settings -> General -> Accessibility -> Reachability -> ON (green slider)
  2. Swipe down on the gesture bar at the bottom of the display