It's not all sugar, there are some actual differences; and especially around async/await there are optimizations that can only be made in the non-transpiled code.
He said async/await is syntactic sugar over promises which it is. And that babel is easy to setup, which it is. Those statements are independently true. No one said the state machine that babel transpiles your async/awaits to is performant, he wasn't making that assertion.
The difference between 1s & 1m lag in D3 has got to be a D3 bug.
