I wonder why this is a new topic then. Isn't it pretty established in either Lean Startup or Design Thinking that when building product, we should talk to/inter

I wonder why this is a new topic then. Isn't it pretty established in either Lean Startup or Design Thinking that when building product, we should talk to/interview/research the people who will be using it? Especially in Design Thinking, it's required to do needfinding, which is talking to the barber in this case. And solutions in the brainstorming stage are certainly not confined within software. We just need to be constantly reminded that our perception and reasoning about the world is subjective and often conscious. As designers, or product builders, we should be willing to understand other people's reasoning, putting aside ours.