That's true logically.
A pure PM role is very fake. Here you atleast have a sword on your head to hold you really accountable because u r responsible for the marketing/branding success atleast.
In PM role, true ownership always lies with the engineering/builders, and any risk of product success being attributed to PMs is purely bogus & fake.
It's made to cushion the blow to engineering, which honestly weakens them because they don't face the heat directly and it's unfortuantely put on cute product managers who didn't even put a single brick in the build.
Further more, why I am against PM roles is that in big majority of engineering projects, a customer research is not really that critical. Product vision is many times semi obvious. So ab good designer + EM who can collect requirements really well will suffice. Now you will argue 'am I really saying PRD is not required?'. Sure let's say it is required, but then when execution happens how many times do you change the PRD and that too based on what? Your nuanced understanding is engineering solutions and feasibility. If this is really the worth of PRD where you figure out the right functionality based on engineering solutioning, what is the true worth of the original prd where EM didn't have to come and tweak. Maybe the solution is just have very few but very experienced PMs to design the customer requirement and let engineering fill in the gaps. We don't need kiddo PMs to detail out nitty gritties of the features, which will always be driven and changed by engineering. EMs can fill those gaps quite effectively.