To expand a bit on the previous post (prompted in part by Gary Richmond’s apposite comments), contraction in language is necessarily to viewed as a stylistic alternative to its unexpanded counterpart, specifically as a colloquial/informal/elliptical variant on a “full” form that is employed in stylistically formal or neutral contexts. This is overwhelmingly the case in English (as well as most other languages), where augmentation as part of a shift to a colloquial or informal genre of speech is extremely rare. Thus nope, which is the colloquial counterpart of no, represents a completely atypical example of adding a segment in order to signify informality instead of subtracting one.
By the bye, the case of nope, while rare, is nevertheless a good riposte to those who maintain that informality is achieved through economy of effort, hence contraction as something to be explained primarily as a physical means. Anything stylistic, whatever its value, is always conceptual precisely because value is necessarily conceptual, always part of the cognitive dimension of human semiosis.
Why contraction lends itself to implementation as a means of conveying informality is an interesting question. There is clearly something about the human mind that tends to regard the patterned reduction of plenitude as informal in comparison. But examining this question further would take us too far afield from language and must therefore be left unanswered for the time being, at least.