I don't know the specifics in this article but usually the analogy I would give is that async/await is to asynchronous programming as yield/generators are to writing iterators.

When you can use yield you can use regular control flow like branches, for loops, etc to write iterators in a straightforward manner. If you can't use yield you instead end up needing to represent all that implicit control flow using explicit stacks and things like that. Similarly, async/await let you write asynchronous code very similarly to how you would write a synchronous version of the same thing.