A leader changing her/his behavior to model more openness & transparency (social) is just an invitation to others, a suggestion, it only creates an option for people to follow:
“Do or don’t either way, life goes on.”
However, changing the systems (how we manage, how we recognize, what we do about learning, and who gets to make decisions, etc) that people operate within creates a new requirement or at least a slightly different choice:
“Do or don’t, change or leave.”
So, it’s certainly nice to have leaders behave differently but it’s far more impactful if leaders put their energy into changing the systems that compel the whole organization to behave differently.