Obligation to use

In all BDSM roles there is some sense of "authority to use" or "authority to engage". Bottoms, submissives, and slaves all enter into their particular involvement with their partner by handing over authority for things to be done to them. It is, perhaps not obviously, then incumbent on their partner to actually do these things.

If things aren't done to them, then they can and will feel dissatisfaction (or worse), and possibly feel that they have been let down or betrayed by their partner.

Tops, dominants and masters can also experience the same form of disillusionment with a partner who presents or advertises themselves as being one thing but who doesn't actually behave that way.

Trust is an important element here because trust is often based on expectations being consistently met, and with a dominant who doesn't use their submissive or with a submissive who doesn't actually hand over any authority expectations aren't met at all. This may not be conscious or intentional.