There are no good dog breeders, or any pet breeders for that matter. In a world where thousands of abandoned pets are put down because there is no room anywhere for them, you have no good justification to purchase a pet from somebody who creates dozens more of them voluntarily to make money.
You were obviously talking about traditional pets, not service animals.
The service animal industry is also largely problematic and exploitative.
Rescue animals can serve as service animals in a large portion of cases anyways, you don't need "purebreds" to work as herding animals, bomb detection animals, anxiety-comfort pets, guide pets for the blind, etc.
I know multiple people who have service/working animals and my spouse and I both work in the pet foster community, so no not uninformed.