The other problem IMO is that most cases that have this option have the bracket so the card sits "upright" and therefore the cable needs to be longer which is usually more difficult to find.
So the notch does make it a smaller screen, thank you for the correction, HOWEVER the size difference isn't enough to justify such a larger footprint. I have owned the Plus and am actually happier with the smaller physical size of the X given the smaller display size is negligible.
I own an iPhone X and like the fact that it has the larger screen but yet it is smaller in the hand than the Plus models. I personally like the X now that I'm used to the differences between the two.