When I was a software engineer, I used to think I was the smartest person in the room, and derided the work of product managers, delivery managers and to some extent engineering managers. I've had experience of engineering roles up to Principal and Hands-on CTO and felt that we didn't need the non-engineering backgrounds at all. Today, I find myself in a senior TPM role for a FAANG who also has "product manager" in h…
The answer isn't more PM's either, though. In my experience when people are struggling, the default answer is "we need more X", be it engineers, PM's, money. It's very rare to have a group that looks at that and says "we need to do better with what we have" and is able to do so.
A good PM will make sure that everything your product team is working on is the correct thing to work on, which is so much more efficient than hiring 2 more engineers to work on those things. A bad PM can come in many different ways, (just like a bad engineer - we've all worked with the Arcitecture Astronaut for example).