Accountability starts with making conscious commitments. To hold someone accountable, you need to agree on expectations. Make them explicit. There shouldn't be any confusion about what the deliverables are. Focus on three key points: What, When, Who
Delegation is a critical part of leadership. There is a limit to how productive one person can be. You can't stretch time. As a leader, the limit to how much you can improve your productivity is flexible. It all depends how you structure your team.