I dunno man, this is a fairly popular take overall, among people who are involved in emotional support training. Also among people doing service training. Also among people that have genuine need for an ESA.
There's a big movement to place greater limits on what kinds of animals can be ESA. Breed wise, if the training was done to the same standards as service dogs, or ponies, it wouldn't be an issue. Way more dogs wash out for behavioral incompatibilities with service than you think.
Hell, I've heard arguments for limiting ESAs to only dogs, though that isn't useful or necessary imo. As long as the animal is either small enough to not be an issue, or is one that can be trained to standards, it isn't like the kind of training necessary is dog exclusive. Dogs are just the best at it.
Anyway, the arguments you're making are well supported by anyone with exposure to the issue on a professional level, so I had to throw the downvote for being at least mostly popular. Sorry, ¯\_(ツ)_/¯