Not only the best kart racer, but the best racing game period.
Controls great, all the items are balanced, lots of single player content and a large variety of characters from different SEGA franchises to unlock.
What really makes it the GOAT though, is the transforming karts and tracks. There are only a few race tracks where all 3 laps are the same, all the others change mid race thus making them much more interesting than every other kart racer where all laps are exactly the same.
Controls great, all the items are balanced, lots of single player content and a large variety of characters from different SEGA franchises to unlock.
What really makes it the GOAT though, is the transforming karts and tracks. There are only a few race tracks where all 3 laps are the same, all the others change mid race thus making them much more interesting than every other kart racer where all laps are exactly the same.