It’s not only about legacy code. Apple’s website layout (especially on all the important product pages, certainly also some overview pages in the store) is all

It’s not only about legacy code. Apple’s website layout (especially on all the important product pages, certainly also some overview pages in the store) is all highly custom, much more like a magazine than a website. That’s on purpose. That stuff is supposed to look different. Making the stuff reusable wouldn’t even make sense. (Though I do not want to claim that what Apple is doing here is a good way to go about things.)