I have to add - in my comment, I was comparing my Macbook Pro to my laptop. My iPad isn’t as useful as a computer as the laptop or a surface computer might be, but it is still a nice machine.
I think that this is more a comparison based on where each manufacturer defines the line between the pad-type computer and the keyboard-based computer. MS saw a gap in the Apple line and filled it.
There, I can agree with you. The MS Surface fills a niche that was going wanting. However, looking at sales figures, it is not a big niche.