You found a terrible co-founder. A terrible co-founder, business or otherwise, will generate terrible outcomes.
One thing that is very important to understand is that a great business co-founder is as rare (if not rarer) than a great technical co-founder. If you happen to find someone like that, having an attitude that they won't do any work, and they won't "do much meaningful work", will not endear them to you.
If they're a great business co-founder, they will have nearly unlimited options, much like great technical co-founders. They might also have great market knowledge, plenty of inside connections, and experience on what to do, and how to do it. And as you brought it up, experience on how to get to product market fit. All of which is invaluable. Further, and please don't take this the wrong way, but their experience in connecting with and evaluating people might have prevented you from choosing the clearly incompetent person that you ended up selecting.