It is a common mistake among many IT professionals to use Scrum and AgilePM interchangeably, which is wrong because there are quite a few distinct differences between them.
Scrum is light weight, meaning its focus is on project delivery (i.e. ensuring the team is working together to build a complex solution iteratively), while, AgilePM is heavyweight, this means it goes beyond the team, delivery, and is more elaborate and robust as it covers the entire agile project management (end to end).
In terms of popularity, Scrum is more popular than AgilePM, because of its lightweight nature, professionals can understand it quite easily.
Furthermore, a Scrum Master is responsible for facilitating or coaching teams, as scrum relies on support from the whole team.
Though a competent Project Manager might be able to act in both their Project Management role and Scrum Master (if they can adapt to an evolving, ever-changing environment), a Scrum Master does not take over the role of a Project Manager.
In conclusion, none of them is competing, it all depends on what you’re trying to achieve. If you are looking at becoming a competent Agile Project Manager who wants to be involved in the end-to-end process, you can opt for AgilePM. However, if you are interested in managing and controlling iterative projects, you can opt for Scrum.