"Since the birth of the smartphone, a battle between horizontal and vertical video has been taking place. "
I don't agry with that:
1. Most of people hand the phone vertically without thinking of the broadcasting.
2. I don't think there is any battle.
I can see 3 vertical video pros:
1. Film and see on the smartphone a portrait format (interview...).
2. Film with 3 smatphones and broadcast in horizontal format (like Napoleon from Abel Gance).
3. In video art when you turn the TV vertically.