If that screen protector you put on your shiny new Galaxy S9 is making it a little harder to interact with your display and, you know, use the phone than you'd like, you can increase the screen sensitivity to make things a little easier.
To access this menu, go into Settings and then Advanced Features, and then Touch Sensitivity (it's hidden at the bottom of the menu).
This is just an off or on party rather than one where you can dial the sensitivity up just a small amount, so you'll need to be ready to go all-in.
By and large, you're only going to want to turn the feature on if you have a screen protector on the phone that's giving you issues. But if you do have a screen protector on and are having trouble, it could be just what the doctor ordered.