This hasn't really been true for a couple years now. Most of the major US airlines have been migrating from cellular to Ka- or Ku-band satellite internet over

This hasn't really been true for a couple years now. Most of the major US airlines have been migrating from cellular to Ka- or Ku-band satellite internet over the last few years. (Including Southwest.) There's some individual aircraft that haven't been upgraded yet, since installing the satellite antenna is a major upgrade. But at least on my flights, most offer it now.