We have some very successful single-founder companies, such as Instacart. We suggest finding a cofounder not for our benefit, but for your own. Startups are hard, and doing it alone makes it even harder.
pg has said multiple times that a major downfall of a lot of companies is that the two founders have a dispute. What is the major downfall of companies with single founders?
Stamina.
It's obviously very rare. However it has been done before [1].
Single founder can work but it's usually not ideal. For one thing, it demonstrates that you can't find or persuade even a single other person interested enough in you and your idea to join up.