Something will change. It always does. The customers didn’t know what they wanted, they didn’t say what they meant. You didn’t understand their needs, you’ve learned how to do something better. Even applications that are perfect in every way are not stable. The application was a huge success, now everyone wants more. Change is unavoidable. It is ubiquitous, omnipresent, and inevitable
Changing requirements are the programming equivalent of friction and gravity. They introduce forces that apply sudden and unexpected pressures that work against the best-laid plans. It is the need for change that makes design matter.