“Having a co-founder for your startup will help you in following ways:
1. Better decision making: The co-founder will help you in better decision making by providing you a different perspective on a particular idea. When faced with a dilemma they can also guide you.
2. Moral and Emotional Support: The co-founder can be your support system in times of stressful situation.
3. Support of Investors: It is said that investors prefer businesses that are run as a team and not by individuals. Having a co-founder can be great here.
4. Division of responsibility: You would not have to take up everything upon you. Responsibilities can be shared between the both of you.
Here is an article to help you further with this question: https://www.feedough.com/why-do-you-need-co-founder-for-your-startup/