The short answer is: probably. That said, it really depends on what runtimes and browsers you’re targeting, plus what language features you’re using.

As mentioned in the article, the polyfill (or the runtime + runtime-transform) is used to expose features not available in the JavaScript engines you’re targeting, and that cannot be added with static analysis + transform, alone.

So the safest, almost brute-force route is to just use it. If bits are a concern, or if you’re only super modern runtimes and a limited set of ES2015 features, you might be able to without (but it takes a good deal of awareness).