Clarity and conviction are real, but I'd add a third: connection — to the actual business outcome. I've seen plenty of PMs with beautiful clarity and fierce conviction building exactly the wrong thing because they weren't anchored to what success actually looks like.

This maps cleanly onto brand strategy too — and the place I see both PMs and founders fail is that they have conviction about the solution before they have clarity on the audience. You end up fighting hard for something that's true but aimed at the wrong person.