Wouldn't the hard part definitely be creating a product that people love? I do understand that asking users what they want is generally underrated as advice, but that's nothing compared to creating a product that really catches people's eyes.
How can you create a product that really catches people’s eyes without speaking to them first ;-) each step in getting there from designing product, coding to speaking to users is a variable challenge that cannot be generalized. For example; introvert coders might find it hard to speak to strangers while an extrovert will flourish but find coding challenging etc. finding the right cofounder that complements you goes a long way to launching a product that really catches people’s eyes.