I'll play the devil's advocate here, but one solution if you want the modern syntax but with full support to old browsers, is to use Typescript (you can use it without any types indeed)
This is a valid Typescript file:
document.addEventListener('resize', e => { console.log(this)} )
Which compiles to the following classic js (obviously, you should not select es6 as the target!)
var _this = this;
document.addEventListener('resize', function (e) { console.log(_this); });
I started to use TS more than 3 years ago, back in 0.8, and it made me able to use lots of modern features with full support of IE8 and others.