Accountability is finite
Here is the funny thing about accountability.
When there are many stakeholders, and one or two of them show greater accountability (and action), the others step back and sit on the sidelines. They step back not necessarily because they feel less passionately for the topic or task in question, but maybe because they see it already in motion with the others, and don't see enough room to contribute.
As a leader, it's important to recognize when to take complete accountability proactively, and when to let your teams drive the action. Too much accountability by the leader may lead to the team either going into a pure executional mode (with the leader becoming the instructor), or the team feeling unleveraged & disconnected. At the same time, too little accountability from the top may send a message that this task isn't important enough, or worse still that the leader is shirking their responsibility.
Creating this balance is an art that depend on the the topic/ task at hand, the team's composition, experience and their drive, as well as criticality of the task. Often, showing intent but leaving space for others to contribute is essential to build collaborative accountability.