The best product owners I have ever had were those obsessed with the product and its quality. Those who didn’t care about to dirty my pretty code to implement new requirements nor the time nor the money. Those who had very clear the iron triangle and always knew how to deal with the client without moving the pressure to the team. And those were the best not because my job with them was easier, but with them I made products what I am proud of.
The worst product owners I have had were those with a technical background.