I agree completely. I was a lead engineer on a product in a situation where we did not have a real product owner or a project manager. While I could manage the team and organize work, I struggled massively to come up with well defined and focused features for us to work.
I would spend lot of time talking with different customers and trying to move that into development, but I was losing so much time I could have spent solving serious technical problems.
Having a good product owner that sees the big picture and can write down a rough specification of features would have helped massively and allowed me to do what I do best.
On other hand, I was also in a situation where product owner depended on me to do his work. That is even worse.
I was a PM in a long ago prior life and, at one point, we decided to bring development managers into more customer meetings. It wasn't a bad idea but they had their "day jobs" so would end up being only in a few meetings. So it ended up as almost mirroring sales where the last customer they spoke with was taken as gospel and a blueprint for what we ought to be doing.
To one of the broader points, in both my personal experience and what I see software PMs doing in my current non-PM role, they spend a lot of time talking to customers.
I worked in a role in healthcare for a few years where I was the lead engineer and sat in on most customer meetings, and even did some field observations. It was an invaluable experience. It was super useful for disabusing me of certain notions I had about which features mattered. I learned a lot about product work from the experience and started asking myself and the team different questions during the development process.
I got to see a broad swath of users with pretty different needs, and learned a lot about how their clinics worked. It was really good for thinking concretely about tradeoffs.
I would spend lot of time talking with different customers and trying to move that into development, but I was losing so much time I could have spent solving serious technical problems.
Having a good product owner that sees the big picture and can write down a rough specification of features would have helped massively and allowed me to do what I do best.
On other hand, I was also in a situation where product owner depended on me to do his work. That is even worse.