It's cool and obviously took some talent, but I don't understand how or why this is proof that no new browsers will now ever be possible. And I also can't see w

It's cool and obviously took some talent, but I don't understand how or why this is proof that no new browsers will now ever be possible. And I also can't see where that is even mentioned or alluded to on the page that this links to. Is it an editorialized title for the post? Can someone explain?