1. A black band across the top of the wallpaper
The menu bar shows the wallpaper behind it. Choose a wallpaper whose top edge is black, or add a black strip as tall as the menu bar to the top of any picture, and the menu bar turns black, with the notch lost in it.
2. Keep full-screen apps below it
Select the app in Finder, choose File › Get Info, and turn on Scale to fit below built-in camera. In full screen it then fills the screen under the notch, with a black band across the top.
3. An app that does it for you
TopNotch is a small free app that turns the menu bar black, so the wallpaper can stay as it is.
Or make it worth seeing
The notch is the one part of the screen that does nothing. Tilora turns it into a Dynamic Island: what’s playing, your next meeting, a download coming in, a call you’re on, AirPods connecting. It grows when there’s something to say, and goes back to being a notch when there isn’t.
Questions
Does hiding it change anything else?
No. These change how the menu bar looks, or where an app sits in full screen, and nothing else.
What does Tilora do on a Mac without a notch?
It draws a small notch of its own at the top of the screen, on an external display too.