It depends - are you a product manager, or something closer to a project manager?
If product, then I (as a developer) want you to contribute things that I can't do (or don't have time to do):
* detailed market-analysis of competitors/features etc.
* stakeholder research
* good numerics/understanding of MVT tests and how to evaluate results, avoiding common causes of bias
I don't want us to vote on features, I want you to have a solid evidence-based approach to prioritise product changes.
I also want you to:
* know the product better than anyone else, including me (if things are only specified in code/buried than that needs fixing)
* showcase your research/evidence/learnings to the team regularly
* collaborate closely with devs/leads/dev manager to balance tech tasks with new features