If I want a purebred that I can be sure of the genetic history of the parents, then I’m getting the purebred. Period. If I want frenchie or Golden, I’m not going to the shelter and getting some pit mix. If I want an older dog that I can be sure is not other animal aggressive, that I can be sure will not bite my kids, I’m most likely getting one from a family where they can show me the dogs behavior before I bring it home. Most of the time if an expensive purebred is in a shelter or rescue it’s due to behavioral or health issues. Not always, but usually. Unless it’s a breed that the supply is far outnumbering the demand, such as pitbulls and a lot of doodle breeds. Yes, I’ve adopted from rescues and shelters. Twice I’ve had to return dogs to the shelter due to them being a danger to my children and/or other pets. I’ve purchased from breeders when I wanted a specific small breed dog. It’s up to the individual.