I doubt you do. I don't think this "saying" applies to anything more than the UI for a webstore.
There are lots of UI conventions across various fields, and quite a bit of them require doc reading to be understood.
Users can be left confused even by basic windowing controls when they switch from Windows to Mac for example.
Not sure where you pull these "sayings" from, but there is no truth in them at all.
I haven't yet met a piece of specialized software -- from Photoshop to Houdini, Maya, Blender, Unreal Engine, DaVinci Resolve, Scratch, Lightworks (in the CG world) to Nuendo, Falcon, Reaktor, Architect, MODX (in the audio/music world) and even stuff like VS Code or Excel -- that didn't have particular gizmos, GUI conventions, order of steps to do things and so on.
Any user of any of those would benefit greatly from reading the docs, because none of those GUI specifics are "intuitive" in any way, but make for very fast and easy operation once they are learned.