> JS of the era was a pain to use; CoffeeScript made writing and reading things much easier

It didn't. Anything you learn / are familiar with will be easier to write - Coffescript was easier to write for people who learned Coffescript. Which in hindsight wasn't time well spent as they would've eventually had to bite the bullet anyway & just learn JavaScript like everyone else.

JavaScript is much much easier to write and read for a person who has chosen to learn JavaScript & has not had the occasion to learn Coffescript (i.e. most people) so you were also doing others a disservice if readability was one of your goals.

> which is the reason it took off

The reason it took off was the Ruby was going through a popularity trend & Rails devs wanted to work in a front-end language that felt syntactically familiar. It was purely aesthetic.