Context: I installed an app called "Scroll Reverser" which will allow me to use the natural scrolling setting for my trackpad and the opposite scrolling setting for my mouse scroll wheel. The application requires the Privacy permission "Input Monitoring". The description of this is to "Allow the apps to monitor input from your keyboard even while using other apps".
So does Apple just consider mouse inputs, like scrolling, an "input from your keyboard"?
The app was recommended by another user on this site: How to separate "mouse" and "trackpad" settings?