I might be missing something, but that test seems to show everything works, it's not a perfect test, as in, it's not obvious what you were focussing on, a page of text is thousands of potential focus targets randomly spaced.
The fact that the focus is successful sometimes suggests it's your technique. Whilst I disagree with the fox's tone and some of his advice (IMO BBF is easier and more predictable than shutter button focus), the point is that what you're trying to do isn't easy, you need to have a thorough understanding of the pitfalls of advanced techniques before you try to 2nd guess.
Firstly, your focus points are larger than the squares in the viewfinder, and your camera needs contrast to focus, so an area of contrast close to your chosen focus point will create frustration*. There's nothing wrong with shooting tricky subjects, but you have to understand that's what you're doing.
*the best example of this is when we 'focus on the eye' and the camera misses slightly because it finds the eyebrow.