A new feature coming to the next build of Android has surfaced in Android 12 Developer Preview 2. It allows users to swipe down on the gesture area to pull down the notification shade. Under the Gestures menu, make sure that Swipe for notifications is toggled on. To do that go to Settings > System > Gestures. To show you why only Developers get to install a Developer Preview, the illustration of the new feature is actually a placeholder that has nothing to do with swiping and the notification shade. It shows the user swiping down on the rear fingerprint button which is not correct. The text under the picture, though, is correct and says, "swipe down on the bottom edge of the screen to show your notifications."
The new setting is working just fine on a Pixel 5. On a Pixel 4a 5G, the controls can be seen in the settings, but the toggle can't be accessed so as to turn the feature on. And nothing related to swiping for notifications can be found on the Pixel 4. But this shouldn't be surprising. Remember, we are talking about an unstable build of software.
Looking at the GIF created by AndroidPolice, we can see how a swipe down in the gesture area brings down the notification shade. It should be pointed out that the new feature does interfere with the new one-handed mode which also debuted with Android 12 DP 2. Both features cannot be enabled and work together at the same time since they are both triggered with the same gesture. But we are still very early on the path to Android 12 (the final version could drop early in September) and this issue most likely won't be a problem by then.