On a somewhat related note, I just added an object and went to the mesh data tab in properties to enable auto smooth and set the angle value to 180. Object was still flat. Contextually would make sense for the object to be set smooth when enabling auto smooth. As it is currently, let be honest - it’s a bit confusing, especially for new users.
edit: I’d even go as far as to rip out the shade smooth and shade flat menu options altogether and rely on auto smooth defaulting to off, with the angle at 180. When ticking the auto smooth(and rename it to smooth shading?) to be on the mesh gets set to smooth, want to have sharp edges? Either tweak the angle value or use edge sharpness(by selecting all and set sharp or by using the modifier if that is more applicable). Or tick that smooth option off again in mesh data tab.