And when laptops do have a spare M.2 slot it's usually intended for an SSD only and is not the right kind of M.2 slot for a cellular (or WiFi) card. And of cour

And when laptops do have a spare M.2 slot it's usually intended for an SSD only and is not the right kind of M.2 slot for a cellular (or WiFi) card. And of course, you'd need antennas. So the whole laptop needs to be designed around accommodating cellular connectivity, with significant changes to the internal layout.