There is a profound and nuanced distinction between the connotations of accountability and dependability. The difference has to do with the locus of control involved. In accountability, someone feels responsible for someone else's actions. This is the standard Industrial era model featured in hierarchies. A superior assigns actions to inferiors and "holds them accounatble" for that which the inferior doesn't choose. It's a external locus of control relationship of dominance and subservience.
Dependability is chosen. People choose the actions they will contribute to the whole. They operate from an internal locus of control. In this context, if there are "leaders" they are inviters, conveners, facilitators, champions and supporters. They do not take responsibility away from others; they empower them with continuous opportunities for dependability. A dependability culture interestingly demands far more personal integrity and honesty than an accountability culture does.
This distinction leads to a transformational question for organizations. Do you want people who are accountable or dependable? My experience over the past decades has clearly shown that in a vast majority of cases, in attitude and aptitude, dependable people far outperform accountable people. Creating high engagement organization is an effort built on a foundation of dependability.