[jaza]

I assume that the vertical recording fad primarily comes from:

1. the people doing the recording being too lazy to rotate their phones, and/or the people doing the recording catering to the lowest common denominator of expecting viewers to be too lazy to rotate their phones;

2. so many "influencer" and related videos these days consisting solely of the narrator's face being right in front of the camera, which makes for vertical being the optimal orientation, due to the human face being taller than it is wide (hence the term "portrait orientation"!).

I also hate it, and I also still shoot almost all my photos and videos in horizontal / landscape orientation. I guess that makes me old.

[floating-io]

IMO, it's also because vertical orientation is effectively the default on a phone.

Nobody expects to have to turn their video camera sideways to capture in the "correct" orientation... but you must on a phone.

[lynx23]

Well, I used to want to do photos/videos in landscape mode. Until I learnt the hard way that orientation detection is not very reliable on (at least the older) iPhones. Had my share of "come on, turn 90 degrees you useless thing" moments, until I gave up completely on wanting to reorient my phone. Since then, it has stayed in portray mode forever.