I am surprised he doesn’t like the more recent additions to JavaScript. I liked ES6 features quite a lot.
ES6 is what makes JS bearable to write modern day. Totally don't understand his point here. Who wants endless nested promise chains?
One of the things Promises solves is nesting. If you're nesting them, you're doing it wrong.
(I don't mean "never nest them"... but if you find you're nesting them, see if you can refactor to "all()" them or similar)