It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change.
It isn’t all over once your software is in the wild. It’s a “lifecycle”, remember? The end of one phase just marks the start of another
Requirements and customer needs are always evolving. As people use your software, there will undoubtedly be more bugs, feature requests. And that’s not to mention the basic upkeep and maintenance of your software.
All of these “requests” should flow back into your product backlog task list so they can be prioritized and become part of your product roadmap.
A system is never finished being developed until it ceases to be used.