How do I make a YouTube video with text-only?
You can create these easily in most video editing programs. For example, in iMovie (which is available on Apple devices), each of these is a Title.  "Title" is what iMovie calls a page of text.  So you create one Title for each thing you want to say on screen, and you add them to your video. Make sure the beginning of every Title fades in from black, and the ending of every title fades out to black.

Once you're done with that, you probably want to make sure you can read each of them in the time they're visible.  I typically leave Titles on screen for as long as it takes me to read them out loud (rather that just reading them silently in my mind).

When you've got the timing done, find music to add in the background. iMovie offers a lot of free, royalty-free music that you can use.  YouTube also offers you free music you can download and use at http://youtube.com/audiolibrary.