With the release of the One UI and Android Pie update for Samsung's Galaxy devices, along with the release of the Galaxy S10 line, you now have the opportunity to dike Android button navigation and rely on gestures.
How to turn it on
Samsung's One UI is not the default for navigation navigation. Instead, the operating system uses the traditional back buttons, home and app switches at the bottom of the screen. To switch to gesture navigation, open the Settings app and go to Display > navigation bar and select the window on the whole screen