There is a service worker that will prefetch all of the event handlers currently in view. So when the person clicks on the button, the browser will fetch the JS, but the service work short circuits that request and returns the JS instantly. They have plans to make the prefetching even smarter by gathering information on which chunks are most used and prefetch those first.
Ah I didn't realise it did that? The homepage still makes several references to lazily downloading JS?
Eagerly downloading JS is something every framework does though and many only download for the current view through code splitting for the current page. It doesn't fix the later two problems..., struggling to find any benefits above existing techniques here :/
