Why aren't they downloading the updates while charging? Shouldn't be too much effort to either install WiFi at the superchargers or run data over the charge cab

Why aren't they downloading the updates while charging? Shouldn't be too much effort to either install WiFi at the superchargers or run data over the charge cabling. Then maybe just update the "local" map data around the supercharger (the next charger along the route will update the next area; no need to update unused maps). Also I'm wondering why updates are generally fat blobs instead of deltas.