There you go again, dismissing 4k and RTS out of hand, you do realise that a 4k image is 4 times more detailed than a 1080p image right? That makes this comment about it instantly wrong before we even factor in other improvements.
If your saying that by taking that GT7 image, making it 1080p and remiving the RTS you can make GT Sport look just as good, then yes, you probably can. But GT7 does have 4k, it does have RTS, it could still look even better closer to release.
You can't claim the images are almost identical and then remove the strengths the next gen hardware has as an argument. Well you can claim what you want, but it doesn't make for a logical argument.
I can say I'm as good looking as Brad Pitt, if you put a bag over his head. You're trying to tie GT7's hands behind it's back and then say "hey look GT Sport is just as good". It's not.