That works both ways. Sure, if someone has all they need to succeed, the distraction of a co-founder might be a problem. For the rest of us, we need the balance

That works both ways. Sure, if someone has all they need to succeed, the distraction of a co-founder might be a problem. For the rest of us, we need the balance, challenge and questions of a peer so that we have to listen and justify decisions. Questions around skills, again, depend on the scenario. I might be an engineer but I sell online and don't need "sales skills" so don't need a co-founder. In other companies, the need for certain skillsets which I don't have needs a co-founder who can give your business the bandwidth. I can't honestly see that either way is always preferable - depends on the person, the company, the market etc.