The basis of any successful startup should be that it solves a problem that matters to potential users. It’s even become part of startup terminology to ask people what problem they are solving when figuring out what their company does. The terminology only serves to reinforce the reasoning that if what you’re working on is not a problem to someone it’s not worth working on.
When deciding whether to pursue an opportunity it’s important to figure out how important the problem is and who it matters to, and don’t think the work stops there. During the lifespan of your company it’s important to periodically reassess whether your initial findings about the problem were correct. Consider whether the research was thorough enough and whether the thoughts your customers have about your product or service have changed since you started the company.