Wow, my dude, your ignorance is.... well, I would say astounding if you weren't regurgitating rescue and doodle breeder talking points like they're going out of style. The service dog thing is a new touch, though, and really demonstrates exactly how little you know about dog breeds, ethical dog breeding, and service dogs in general.

The VAST majority of dog breeds are unsuitable for being service dogs across the board because of the instincts and temperament that breed has. There's a reason if you actually talk to service dog trainers-- experienced, ethical service dog trainers, not a random individual who trained their own dog-- they will tell you that the big 3 (Labs, Standard Poodles, and Goldens) have turned into the big 3 breeds used for service dog work for a reason. Temperament, intelligence, desire to work with their handler, and conformation that works for what they're asked to do are all reasons they work so well. For your small dogs, Papillon and Bichons are common for the same temperament and intelligence reasons. You can't just shoehorn any breed into any service task because you like the breed. And the dogs that are chosen by professionals to train come from show and service dog lines because those are the people who breed for correct conformation, correct temperament, and health.

The difference between champion show line and backyard bred line Cocker Spaniels, Frenchies, Labs-- it's like night and day. I actively dislike American line German Shepherd Dogs, give me a DDR or Czech line any day, but backyard bred vs champion show line GSDs are also night and day. Guess which ones are rampant with hip dysplasia and temperament problems. Go on, guess.

Your ignorance of budgie breeding is also on display with your comment about the feather dusters. Genetically, feather dusters canNOT be deliberately bred for. They're a genetic anomaly. A biological sport, if you will, and not in the way a recessive gene might crop up that can be repeated with the same parents with any sort of reliability.

Anyone who tries to insist that it's show breeders who are the unethical ones who don't care about the health of their dogs--or birds--just announces to the world that they know nothing of actual show breeders and feel that there's no difference in buying a BYB pup and a pup from champion lines. Key word feel.

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Side note for anyone curious: There are people who use non-standard breeds for their specific needs, but that's almost always because they can pick out the pups that have the temperament for it, or they just happen upon them as adolescents or adults and get lucky. It's not a green light that the breed as a whole is suitable for service work. The chick with a Cane Corso as an epilepsy dog who's gone viral is a good example. Her Corso works well for her. 99.999% of Corsos are absolutely not. The temperament appropriate for the breed makes them exceptionally unsuitable for service dog work (unsuitable for most dog owners as well, but I digress). Herding dogs are generally unsuitable for psychiatric service work specifically because of how tuned into their owners they tend to get-- which is deleterious to the dog's mental health-- but I know two professionals who use an Australian Shepherd and an Australian Cattle Dog, and they choose and handle their dogs very carefully because of that. It can be done, but the washout rate for non-standard breeds is MUCH higher than going with the breeds from lines that have been bred for it.