The phones are getting bigger and bigger, so it's getting harder to reach the message box. But Samsung is here to save, as they have introduced a UI for Galaxy devices a gesture that makes it easy to access the message box on your home screen.
On your Galaxy S8, S9, S10 or Galaxy Note 8, Note 9 or Note 10, you no longer need to extend your thumb to the top of the screen or use two hands to access the message tray. You can be a one-handed Galaxy guide with this simple gesture that makes navigating to your message box as easy as swiping down. Swoosh.
Enable Sweep Down for Notification Panel
Long press on any blank space on your home page and then select "Home Screen Settings." From here, you can find and turn on "Swipe down for notification panel."
When you turn this on, when you are on the home screen, you can quickly swipe down to lower the message tray with a gesture. To be clear, it only works on the standard screen. If you use a custom starter you will usually have their own version of this gesture.
It is also worth noting that this does not work on the Bixby page on the left home screen. It doesn't work when you're in your app drawer or when you're in other apps. So it doesn't work everywhere, but it's still pretty handy!