The value of a PMP is high, but some organizations may have perceptions of diminishing returns, especially in highly agile environments or when teams are self-organizing. In these cases, the traditional "waterfall" project management approach may be less effective. PMPs may have to adapt their style to become more facilitative and coaching-oriented rather than directly managing. On the other hand, even within the agile environments, having a PMP helps put much structure to make decisions, and helps align with higher business objectives for that project.
In conclusion, the responsibilities of a PMP in software development projects are of great importance and necessity because it ensures that such complex, dynamic projects are delivered successfully, on time, and within budget. The role might change in an agile environment, but it still remains a determining factor in the success of the project. Saving Changes...
A PMP just proves that an individual possesses PM knowledge and a theoretical ability to apply it to scenarios. It does not confirm their actual competency. As such, you could have a certified PM who is excellent at leading teams in both predictive and adaptive contexts or another who struggles in the latter.