The Pixel has a clever way to add grip.

I don't like cases, but I have to use one for my iPhone. As nice as the iPhone's metal back and edges are, they don't offer any grip, and I've dropped and dinged my iPhone a couple of times as a result.

The glass inlay on the Pixel's back doesn't look particularly nice (it looks better on the white model), but it's actually a great grip for your index finger, which makes the Pixel feel more secure in your hands.