Useful customization & personalization arrives long before a new product needs to exist. There also isn't much point building a real product while AI is still advancing relatively quickly. In product terms, if you starting building something in 2024 and are ready for release in 2027 your product better be magic or a video game.
NYT > A.I. Was Supposed to Give Us New Killer Apps. What Happened?
According to the AI creators, AI itself is the ultimate killer app - literally.