I am just an amateur.
Why do you buy this if you can purchase a more expensive Iphone with worse quality and less control? Yes, I am being ironic.
We have two eyes arranged horizontally. Landscape video o cinema is the natural thing to do. Vertical video sucks. It is not mandatory to shot vertical videos only because we all have smarphones and we don't know to handle them.
They have a new sample footage:https://youtu.be/mIAfxj7nd9k