Founder burnout happens a lot. A good co-founder can help shoulder the load.
All right, so the question is: I'm feeling burned out; my co-founder isn't. What should we do?
Look, I think the reality of building a company for years and years is that there are going to be certain times where you're feeling more energy and times where you're feeling less energy. The same is true for your co-founder. That's a big part of the value of having a great co-founder, is that if you're low on energy on a given day, maybe they can step it up and carry the load that day.
The way that it's phrased, though, talking about burnout makes it sound like a longer concern, and it's a deeper concern. You know, I think my question back to whoever's thinking about this is: What's underneath the burnout? In my experience, there's almost always some deeper issue that's causing these longer-term feelings of burnout, and those issues are usually unique to the situation in a way that makes it hard to give blanket advice to someone who's feeling that way.
Ask that deeper question and understand what it is that's causing you to feel burnout, because without solving that underlying problem, that feeling is not going to go away.