Some (perhaps over simplified, and too quick) anologies come to mind:
1 - Taking off, flying and landing an airplane, can all be learned by watching videos.
2 - Driving and parking an automobile (or any other vehicle) can be learned by watching videos. Even racing them can be learned by watching a video.
3 - Etc.
Also of note:
"Aikido is one of the oldest and most widely-used martial arts forms in the world.
It is being taught for centuries as a form of self-defense and protection." & "...A good aikido training school is needed to achieve this."