First of all, Surface Laptop would be better compared to the Macbook Air as the Macbook pro does have a dGPU and is therefore Surface Book's competitor.
Now the Surface Laptop's keyboard is not just about the Alcantara fabric, they also needed to develop a whole new technology to build the speakers beneath that keyboard. Then it's the screen - it's the thinnest panel ever used for a laptop screen, even thinner than any Macbook's. Not to mention that it supports touch and pen inputs, whereas Macbook Air doesn't. It also has older processors and therefore also less capable integrated GPU.
For me Surface Laptop is the clear winner here for innovation, even though nobody asked them for innovation - just to make a device with traditional laptop form factor (that's what Panos Panay said).