The navigation and status bars aren't very noticeable on the S10's home screen since they're transparent. The status bar will even change colors to match many apps. Unfortunately, the same can't be said for the navigation bar.
The navigation bar still shows up in its old, opaque layout that takes up display space when using most apps. In the past, Samsung gave you the ability to hide the navigation bar with a tiny button located on the left-hand side of the bar. With the S10, this option has been ditched in favor of gesture-based navigation controls.
Compared to the traditional navigation bar, the new gestures free up screen real estate on your S10 for a more immersive experience. They're even better than the old method of auto-hiding the nav bar, as the gesture controls do away with the extra step of tapping a button after swiping up to reveal the navigation bar.
To try out the new gestures and get rid of your navigation bar, head to Settings and select "Display." From there, tap "Navigation bar," then select "Full screen gestures" to enable the feature. You'll see three tabs at the bottom of the screen letting you know where to initiate the gestures — if you don't want these, disable "Gesture hints" at the bottom of this same menu.
Now, you'll just need to swipe up where you used to tap. So all you need to do is swipe up from the bottom-left to open the multitasking UI, swipe from the middle to go home, or swipe from the bottom-right to go back.
These options will be reversed if you changed the "Button order" option in the "Navigation bar" menu depicted above. Home will still be in the middle, but back will be on the left and multitasking will be on the right.