This is grim:
If you look at the data below on how popular websites today are actually transpiling and deploying their code to production, it turns out that most sites on the internet ship code that is transpiled to ES5, yet still doesn’t work in IE 11—meaning the transpiler and polyfill bloat is being downloaded by 100% of their users, but benefiting none of them.
Any time or effort spent getting your JavaScript working in IE11 is wasted time that could be better spent making a better experience for users without JavaScript.
I agree with this approach.
With a few minor omissions and links, you can create a site that works great in modern browsers with ES6+ and acceptably in browsers without JavaScript. This approach is more sustainable for teams without the resources for extensive QA, and more beneficial to users of nonstandard browsers. Trying to recreate functionality that already works in modern browsers in IE11 is thankless work that is doomed to neglect.