You're the founder so you surely know what you founded but going further, you can't know it all and when you have someone who is specialized on what you are not so good at, you as a founder will get to learn from them and get better from there.
But like I said, it's better if a founder is business competent
I actually wrote something about this sometime ago. Maybe I will share the link to you so you would read through
I think it's all about putting it into perspective though, there are some cases when it is a must you be business competent as a founder but there are other cases when it is fine to learn on the job