Just build something people want" is the most useless advice in entrepreneurship.
Yeah thanks. Revolutionary. Build something people want. Never occurred to me.
The hard part isn't knowing that people should want it. The hard part is figuring out WHICH people, how badly they want it, whether they'll pay for it, how to reach them, how to convince them, and how to keep them. "Build something people want" skips all of that.
It's advice that sounds wise because it's simple. It's useless because it's simple. The entire challenge of building a business lives in the details that sentence glosses over.
Tell me how to find the people. Tell me how to test demand before building. Tell me how to price it. Tell me where to market it. Those are the questions. "Build something people want" is the motivational poster hanging above the questions.