I think anybody can get a doctor to certify that an animal is an emotional support animal. I know someone who's moving to Europe in a few months. They just got their large dog certified as an emotional support animal and have bought a first class ticket for her. These people travel at least 1-2 weeks a month and board the dog while they're gone, so they obviously don't need the dog for support while they're traveling.
If I paid for a first class ticket, I would not be happy to find a dog in the cabin and have to watch doggy diapers being changed.
I still cry when I remember how an airline refused to let me fly with my emotional support alligator snapping turtle, “Cuddles.”