For me GTS has fundamentally changed how I see and play racing games.
Racing against AI seems so arbitrary now. It is set up so you can win, and if you can't in one car another will do it, or you make some mods to beat people, or you learn the adaptive AI tricks, avoiding what triggers them to "cheat" by doing insane catch up and cornering speeds.
I want complex to drive cars that require certain techniques to get the most out of them. (Kaz speaking about the physics recently makes me worry the game won't move forward much here)
I want tracks that are great for racing on in technical terms, not just a wide variety of interesting looking locations to drive around until I get bored.
So many racing games including GT you enter, you win, you progress, you get new cars. Repeat.
GTS broke the cycle, I now prefer racing against humans even if they are better than me (They usually are better than me). It should be a racing sim, not an ego massaging sim!
How I wanted the GT of old when GTS was released. I picked it up 6 months later in a sale. Yet now I don't care about what is missing, sure add more tracks, more cars but what I want is more online modes, knockout competitions, leagues, types of racing. More ways of playing against people online. If they do that with a bunch of new content for GT7 they could make e̶v̶e̶r̶y̶o̶n̶e̶ most people happy.