I think the best way to identify a winning product is to start with a customer.
By asking the right customer development questions you can learn about their pain points and what’s of value to them.
From there you can see if others like them also have the problem. If you start to notice commonality, you can start shaping a product around them.
Starting with a product idea and asking who would want it CAN work, but I’ve seen it be difficult and restricting in practice.
Bottom line: To identify a winning product, instead of asking “who wants this?”, ask “what does this person want?”