What value does a project manager bring? How do they benefit the technical members of the team who do the work (e.g., the software developers)? Why should software developers prefer to have a project manager as part of their team? What are some reasons that might make them lobby to hire or recruit a project manager to join their team, if they don't already have one? How does a project manager make their life better?

Please pretend you are explaining this to a software developer (or other technical team member), and explain in language that they would appreciate.