This reminds me of a similar video from a few years ago, one which got debunked.
In this case however, it looks like the comparison was skewed in favor of GT Sport. While both are at Brands Hatch, GT Sport is on the wide first corner, but Forza is on the tight hairpin afterwards.
Regardless, I hope I don't have to race with ai much anyway. I need to get that S driver rating.
"Never argue with stupid people. They will drag you down to their level and then beat you with experience."
-Samuel Clemens