

As much as it would be convenient, a plane simply does not have the electrical capacity to supply all passengers with high wattage USB outlets. Large numbers of high-capacity of lithium batteries are a solution, but are also a risk and given the recent number of fires caused by faulty Lithium battery packs, it’s unfortunate but reasonable for carriers to move to restrict them for the sake of passenger safety.


As I understand it it’s been the standard since 2.0 and continues to be the case, even for high-power systems. From personal experience of trying to make a USB-C USB killer for PD, it’s also just damned difficult to do. USB is an extremely resilient standard.