It's not new indeed, but Apple was the first to turn custom in house chips into a major selling point. For example Samsung was vertically integrated for a long time, with their in-house Exynos chips and modems, yet they couldn't capitalize with that in their phones, as they often fell behind Qualcomm in CPU-GPU performance, modem reception and battery life.

Being vertically integrated is not enough if those parts you're making in house are mediocre and don't enhance the final product.