When you are creating a startup or a side hustle you should be your first customer.
If you would not be a customer then you need to find a different startup or side hustle. There is always competition and if you would not be a customer, there will be a competitor who would be. They would understand the product better, relate to customers better, and understand where the product is going better because they are a customer.
When you are a customer you can improve based on what you would want. When you can create something that you love, then all you need to do is find more people like you.