This is good advice, but in my case the "product owner" was too invested in seeming competent (by, e.g., over-confidently and over-emphatically making decisions

This is good advice, but in my case the "product owner" was too invested in seeming competent (by, e.g., over-confidently and over-emphatically making decisions that turned out to be coin-flips). Finally, there was no accountability for product ownership; other than the engineers, no one at the company was positioned, or willing, to notice/address the delays in the project that were caused by the product owner changing their mind arbitrarily. So, while I did spend a few months documenting all these issues, the company itself had not made room for engineering-led process improvements. Noticing that, I started spending political capital on trying to fix it, which is incredibly stressful, slow, and unrewarding work. After a few months of this, I finally came to my senses and realized that, this not being my company, I would not accrue any of the benefits of improving their processes. Time to leave. The lesson, for me, has been to avoid working at companies that are either not product-focused (in which case engineering is just a cost-centre, having extremely low status within the organization), and to avoid stubbornly non-technical founders (i.e. any founder/owner who refuses to care about their engineering department beyond asking "is it done yet?").