Hi Kunal,
Cordova plugins are enhanced and included in SMP as Kapsel .
If you prefer to include SMP in your application development process , you can very much use the Local storage capabilities from the Kapsel plugins and develop the application.
But if SMP is not included in the application development process , you can follow the above guides and achieve offline capabilities with local storage API of HTML5.
You can develop UI5 applications with / without the SMP?
the choice of the application architecture depends on the business process you would like to mobilize .