Your point is quite valid if your definition is true. And it isn´t. Product Management vs Project Management is an old story and I can see your point based on “what people pretend to do” instead of “what´s the job”.

Shortly: Product Management ensures the delivery of value, Project Management ensures compliance. Unfortunately this is what we can see in organisations (you are right), only because most of Project Managers don´t do Project Management.

Let´s take the Bible of PM (PMBok). Since the beginning, a Project is defined in 2 big parts: a Product and a Process. Usually a Product Development starts as a Project and then get bigger in something called a Program. A project is timebound, a program can have a collection of projects and support activities.

In the other hand, Product Development focuses on the development of a new solution and always has an eye on product lifecycles to identify opportunities or old solutions/versions to decommission and withdraw.

Difference is the level of engagement. That´s a differenciator in digital development.

No?