SAP Fiori is designed to provide the new generation user experience of the most broadly and frequently used SAP softwares thus they could be accessed widely in tablets , PCs along with mobile devices.
The grid layout design would help the UI designer to build UI which could fit to a wide range of screen resolutions and make UI components fit in a proportion to other components. While, screen would be bigger , the components also would be expanded in that size in a specific proportion defined by the designer.
Not just the dynamic UI, most amazing feature is to enable role based user activity design in applications. In today's business , actions are role based and in most of the cases companies want to automate the role based decision making workflows. Fiori UX templates and patterns are designed in such a way thus common business role based designs could be implemented faster.