Neither did I say that there was any need to make all metal objects bonded to electrical grounding system.
The scope of discussion is much more limited: whether the criterion is worthy of becoming a requirement.
Seems we are going in circles with the conversation. Bottom line and kind of what this thread started with is that we commonly do use grounded conductors for circuit conductors, particularly at the 120 volt and 277 volt level in the US. If stray voltages are a concern, my suggestion is not to use grounded conductors for anything except for equipment grounding, or minimize the use of grounded current carrying conductors as much as possible, then there will be little or no current that can go stray in "normal" conditions.
Then the conversation kind of shifted to bonding of metallic items - especially those that have little or no risk of becoming energized. If you want to see something in particular to be included in what the NEC requires to be bonded then you are welcome to submit a proposal and a reason as to why, remember it needs to be convincing enough reason to the CMP or they will reject it.
I don't see a metal railing that is fairly effectively isolated from earth and no electrical equipment attached to it having much of a chance of being accepted as something the CMP will think must be bonded, but nothing says it can not be bonded either.