Definitely should have had more than one rung. Perhaps something like this from the side:
=====|
|=====
A lower bar for command well-dwellers to lean on, an upper bar for the crew on the level above.
As I recall, Jeffries really would have preferred a flat floor to the bridge, perhaps for this reason. Personally I think the railings are a nice bit of nautical visual continuity... another both in and out of universe reason for the pit is that it puts the navigation controls lower than the Captain so he has a view of what’s happening on the screen instead of the back of the navigators heads (which is both a practical thing and so that the camera we the viewers see the show through can do the same). Really that’s more an argument for putting everyone in a pit, though, such that the commander can see every station plus the screen clearly. Or having the chair on a pedestal. Which conjures images of someone trying to grab the Captain, only to have them causally boot them in the head with their 60’s healed boots! I suspect that’d be a different kind of space OSHA violation!
I feel like, if starships actually existed, every railing would probably be wrapped in rope, since there is zero way that tradition will end aboard ship even in the 23rd century!