It might be that with the find of the new glitch moderators need to be more careful to find which runs are using them instead of using two player mode.

There are also some tracks that benifit from using two players as you can see if you look at my pepe silvia run you can see that in the end that my best time is not the one submitted because its a 2 player run that can skip some sections

you can actual do this easier with using 2 player and reseting the car on one side and it allows you to race more consistently