Hmmm… Wouldn’t say the bolded part is true at all. 7 and 8 changed the gameplay a lot. 7 introduced gliding and underwater driving. It also had a VR Mode and more items in use at a time (Lucky 7). 8 introduced antigravity AND the engine allowed them to defy physics - On the Mario Circuit Mobius Strip, realism would determine that the vehicles fall when you’re upside down, but you can drive and use items while you’re in that position on the course, maintaining the sense of speed. It also allowed camera manipulation because the camera follows the kart from the back, and in real-time gameplay, you would think you’re playing a regular track the right way around. However, when you watch the replay, that’s when you realise you were upside down!! Another example of this is on Shy Guy Falls - Realism would determine that the force of the currents send you backwards and overpower you. But on this course, there’s a point where you’re driving UP a waterfall, again at speed, and where you can get boosts with the antigravity mechanic. Once more, the player might not immediately notice this in real-time play, as one is naturally preoccupied with trying to win the race to pay attention to such details, but seeing it on the replay blows my mind. There are many details like this littered throughout the game, and the sum of these intricacies bring new dimensions to the gameplay.