It can also be a result of the XY problem. Person wants to do Y, they imagine a software that does part of the hardest parts of Y (call that part X), and they commission software that does X. They then commission a ton of other small parts of Y to be added to the software of the course of years. Whereas an all-inclusive software to do Y from the beginning would have been simpler.
This issue can be avoided by product leads with vision for the entire problem.