Consistency turns distinctive design into a recognisable brand
A consistent design system gives a brand one coherent visual and verbal presence, even when its communications change by audience, channel or campaign. Brand consistency matters because inconsistencies muddy the brand message and create confusion. Over time, disconnected logos, visual quirks and uneven applications can make sub-brands appear unrelated to the parent organisation, weakening the power of the overall brand. A design system should therefore define the principles that hold the identity together, not simply prescribe repeated layouts. Typography, graphics, visuals and messaging all contribute to how a brand is recognised. The purpose is to make distinctive brand assets and creative decisions work together consistently, so audiences encounter the same underlying brand wherever they meet it.
Sources: Why bold design is good business, Designing an Authentic Emotional Connection