The benefit, even for small applications is reusability. I have already published a <ng-markdown> component to GitHub that can be installed via JSPM and import

The benefit, even for small applications is reusability. I have already published a <ng-markdown> component to GitHub that can be installed via JSPM and imported as an ES6-module. The new module and web component standard are going to completely change the nature of how web applications will be built in the future. Unfortunately, it'll be a few years until both standards are natively supported across all browsers. Until then, web component frameworks like React, Ember, and Angular2 are the best alternative. If you don't like frameworks, you can use polymer to as a web component polyfill but I've heard it adds a lot of overhead for what it provides and has some quirks of its own.