It depends on whom you ask. I am more comfortable in following video instructions than reading a long article. However, as others have mentioned; you could do both at the same time. I.e. you could embed the video in the article itself (and have written instructions as well, if it's a "how to" style topic). That way, you could rank in the SE as well as getting free views to your video; all at the same time. It's a win win.
Another reason to have a written version is because you don't have full control over third party platforms. If YT decides to take your content down tomorrow, you will still receive visitors; and just replace the video with a new one.