Here's a criticism I have, and some of you may consider it to be a "hot take" but here goes. There's simply not enough cars in the game. This is a criticism I've shared about GTS as well. Only 420 cars? For a full-scale, "retro-inspired" GT game? With the exception of 1 and 3, all mainline GT games have had a significantly higher amount of cars. Yes, I will concede that there were duplicates and many closely related cars in those games, but still over 420 unique car models to choose from, easily. The sheer number of cars to drive is what makes Gran Turismo, Gran Turismo, and is why the series has appealed to me in a way that no other racing game has. To say it bluntly, yes, quantity over quantity. I'm not sure if there will be more cars added to GT7 in future updates, or there will be DLC like in GT5, but I'm hoping there's going to be much more than just 420 cars. A low car count also kind of invalidates the point of the Used Car Dealership, one of my favorite features of Gran Turismo games. The charm to the UCD is showing up and never knowing what cars will be there, and in GT4/GT5, where there were hundreds and hundreds of cars relegated to the UCD, that charm was always there. If there are only a small number of cars in the UCD, then it gets much more predictable, and loses its lustre altogether.
Also, there does seem to be a possibility that GT7 will have cars that are very similar to one another. For example, in the UCD, I noticed a 1988 Silvia K's, while the License Hall had a 1990 Silvia K's. The only main differences between the two seem to be wheels, and a slight power increase.