Part of building a successful product is sticking to a particular persona. It gives you ample visibility of existing pain points of customers.
With persona in mind, we know what we are not building. It keeps us more focused.
People building large enterprises did not start it from day one. They learned and moved up the order knowing specific pain points. In short, they kept customers and their persona at the center.
If you are building a product, start small with a niche, pick a persona, stick to it, learn the trick, satisfy the user and move up the stack.