There are numerous BA and other carrier threads on the exact same topic. Hopefully these will be merged at some point. They have little to do with BA and rather the technical requirements of the aircraft.

When both the aircraft and the airport (runway) are so equipped, the technology becomes useful but subject to RF interference from devices which are powered up (having nothing to do with "airplane mode").

Indeed the number of people apparently willing to sacrifice their life and the lives of others for a few minutes of screen time is quite astounding. Or, the middle ground where the interference causes a diversion.