Antonyms for the phrase "holding the reins" could be "giving up control" or "releasing authority." Sometimes, it can be difficult to relinquish power and let someone else take over. However, there are instances where it is necessary to do so. For example, in a team setting, it is important to trust and let others take charge when they possess the necessary skills and expertise. Additionally, it can also be beneficial to step back and allow room for creativity and innovation. By letting go of control and allowing others to take the lead, better opportunities and results could be achieved.