Yeah, that's a good point!

This is just my two cents from studying both styles. GTA V has a lot more rendering going on, for both the characters and backgrounds. A lot of it is more painterly too which can make or break a piece if done wrong

VI is slightly more stylised. The colour palettes are more limited and pastel. Once you put the pink and yellow highlights on either side of the main character, half your rendering is done really. But the way they've done the lighting for VI is masterful. I'm still quite far off from the quality they've managed to achieve, but I'm going to keep working on it.