True; in many instances I detail the part and add the inseparable press-in feature in a separate view with a different model in the drawing. I don't use a PDM and therefore don't have to account for build levels, and the part and assembly can have the same name.
However, convention for sheetmetal as an inseparable assembly is to show the hardware in all views. Even the opposite has happened where the only Pem hardware was threaded fasteners and the manufacturer offers a great discount for using pierce and extrude - tap options. Suddenly it goes back to being a single part! Fortunately this is easier to solve as I just leave the assembly in the drawing. I generate engineering requirement drawings, so I don't concern myself with the shop practices. I don't generally offer flat patterns either. I might use them as reference for specific detailing requirements.
All in all, I like the way Cadkey dealt with views... "it's just a viewport into space". You put 3D stuff in front of the port, and you see it.
Obviously there are challenges to changing models in drawings. But it is clear to me there is a need for it. As "Z" argument... I can see composite capabilities in part files to deal with this but even that is a long shot.