>>5041401 (OP)
the answer is very easy. anyone with a service animal is asked "what specific service is the animal trained to provide on your behalf?". this is the ADA requirement and is allowed to be asked. if you can't answer, or answer with a vague concept, its not a legally compliant service animal.
the root problem is businesses don't give a shit about anything but making money and so will happily let people take their stupid fucking "emotional support animals" to piss and shit all over the store as long as the business gets paid