ES6 is a tool for translating new Javascript functionality into syntax that is accepted by older browsers and browsers that suck....cough IE...cough
Transpilation is taking code from one language as the input and translating it into an output that is code in another language. In ES6, this is specifically taking newer javascript functionality and translating it backwards to allow developers to use the newest features without worrying about shitty browser incompatibility (still looking at you IE...).
Looking at the ES6 Features link below, discuss one update from ES5
and if it seems useful/superfluous
I think being able to export functions and values as modules and have easy access to module loaders will go a long way toward promoting organized code. If working on your code in the future becomes easier, the cost of time spent on organization can be more than worth it.