I suspect what you are really lamenting is the effects of poor leadership that does not grant a "product manager" (which is really a misnomer) the authority and autonomy to be a "product manager".
As you imply, that role is really more a director role, not a manager role. A manager managers, a director directs, including the vision and product market fit. Most Product Managers I see do not have that authority at all, and at best are constantly having to convince "leadership" like some door-to-door salesman, rather than simply updating leadership in an advise and consent format.
As a Product Manager (not Program or Project), this has been my lived experience of the devolution of the profession.
We want PMs to understand the market, the tech, the customer, and the economic value of building a product.
We then ask them to tell us when it will be built, down to the discrete feature and function, be a technical expert for the field and engineering in the product space, ask them to convey the roadmap and timeline to customers and prospects, build reports about everything from utilization to capacity, save deals by changing timelines for “just this one feature”, participate in product marketing, and understand how their product space co-exists in the complex product offerings from a company.
“You are the Chief Product Officer for your product!” is the promise and rallying cry. That’s not an accurate description of what most PMs do and even fewer are capable of doing.
As you imply, that role is really more a director role, not a manager role. A manager managers, a director directs, including the vision and product market fit. Most Product Managers I see do not have that authority at all, and at best are constantly having to convince "leadership" like some door-to-door salesman, rather than simply updating leadership in an advise and consent format.