One of the aspects of reliability is it touches many groups within an organization. Often getting electical and mechanical engineering groups to talk to each other to solve a problem is difficult, as just one example. The bridge of a reliability leader wanting to solve the problem for the improvement of plant availability or improve product reliablity allows a diverse team to work together.
We all generally want to improve reliability. Many just don't know how to talk about the problem as it relates to relaibility.
Being the bridge, or better, the leader that enables the group to see, understand and solve problems, is reliability leadership. We often do not have controlling authority. We do have significant influence though.
Reliability is important to get right for the companies profits and brand reputation. Working to improve reliability and leading those efforts is rewarding. It is also fun.