Video is harder to control than text. It’s harder to browse, to navigate, to search, to pause. Text gives you more of an ability to go at your own pace and to take just what you need. When you need a very specific piece of information, video is a real pain.
It’s also time consuming and expensive to create video. There is, of course, a place for it, but it’s frustrating to hear nonsense like “people are visual”, “nobody reads” etc. etc. when text is such a flexible, efficient and incredibly sophisticated means of communication.