it's hard to say.
you loose some sharpness and clarity when downsampling like this. you can see this on a macbook pro retina, if you choose a resolution that isn't directly dividable by a clean number and compare it to a resolution that is. but if you don't compare it directly, you probably won't notice.
but if you compare the image from iphone 8 to the iphone 8+, the higher PPI will more than make up for the loss in downsampling.
but comparing the X to the Plus, it might add to the gap in sharpness/clarity, in favor of the X.