Without maintainability, adding a new type of input or feature will break existing features. Doesn’t matter how quick it is to write from scratch, if you want

Without maintainability, adding a new type of input or feature will break existing features. Doesn’t matter how quick it is to write from scratch, if you want varying inputs handled by the same piece of code, you need maintainability. In a way, software development is all about adding new constraints to a system and making sure the old constraints are still satisfied.