Apps that have been updated to work with the notch will flow around it. If you have an old app that hasn't been updated, you can enable the "Scale to fit below

Apps that have been updated to work with the notch will flow around it. If you have an old app that hasn't been updated, you can enable the "Scale to fit below built-in camera" option on the executable and it will show the full menu bar under the notch, exactly like it worked before the notch existed. Best way to think about the notch is that it's not subtracting from your 16:10 screen, it's just pushing the menu bar up into the area on either side of the camera. It's previously wasted space that now takes your menu bar so you get the full 16:10 screen for content.