Genuinely confused about this and an answer would be super helpful; Why are emulators banned for EVERY game in the series except the NDS ones?

In my opinion emulators should be unbanned; but there might be a (good) reason they're banned.

Also you guys should set up a discord ;)

We do have a Cars speedrunning discord if you want that: https://discord.gg/kGdjBUp As for emulators being banned, I don't know about most games, but I do know why for MN (because I was the one who did it). If you're going to use an emulator, for the most part they're used for TAS, and so because of that one would have to go through a lot of time to put together a TAS that might be just about as optimal as the current WR run, so because of that we ban emulators in MN. Granted, I know that most emulator runs AREN'T TAS, but the thing is that if you're going to use an emulator, the quality of the run itself just might not be as good as a physical copy or download from Steam or something, at least in my opinion. Again, can't speak for other Cars games.