I have a Sony A7 III. So what I tell is about this camera.
The default settings in the camera are for exposing an in-camera JPG (a devleoped photo). The same applies for the live histogram. However some cameras, like mine, allow you to change those settings and the histogram. I do that for landscape photographs, the reason is that I want to get out as much as possible from the dynamic range and expose that I don’t clip highlights.