Upvoted. I'm actually surprised this is still an issue considering how far back this issue dates. I would be interested to hear if there is any "official" explanation as to why Revit hides stair elements when in an Reflected Ceiling Plan, or why they are specifically avoiding addressing this gap.
It should be possible via transparency or other means to allow treads and landings to be visible in an RCP. If you tab-select a stair, you can actually cycle through the various pieces and select them, but they can only display temporarily. This is what we want to see! Even if there was a subcategory of whatever is masking the bottom of the stair to be able to turn off, that would work. In this case, this a stair in the middle of a space, not having a door to a "stairwell" makes it very ambiguous as to what direction the stair is going or if there are intermediate landings on this level that require lighting.