No new product can be created if the conditions for their creation are not right. First, the technology must exist and be at a practical enough level. Second, the product must be economically viable. And third, the product must be politically and socially acceptable.
The key to being a master of product development is to have a keen sense of how these three factors are evolving around the products that you are interested in creating.
It is valuable to identify the products that are almost ready to be created, but are just waiting for one or two of the necessary conditions to be correct.