Below are the advantages of the SPFx webpart:
- Capability to create Responsive UI using Office UI Fabric
- SharePoint Framework is available as a “No JavaScript Framework”,” React”, “Knockout” thus, it provides a flexibility to choose the JavaScript framework to deploy the solution.
- With the SPFx solution, the user can experience responsive property pane, in which when they can modify the configuration or settings and check its effect without refreshing the entire page.
- Developers can use Typescript to build their solution and write a code very similar to C# language in the SPFx. Also, TypeScript is an object oriented and typed code language.
- It provides Structured Client-Side Customisation
- The SPFx model supports all the browsers and devices such as desktop, mobile and tablets.
- The SPFx solution is future proofed i.e. it will not be deprecated within few years as the future development is based on the SPFx model.
Refer this link for Prons and Cons of the SPFx.