Swallow, great you found a lovely dog that suits you family. I am not judging people who get purebreds.
But what I was pointing out is that this whole emphasis on going to so called responsible breeders is not to the benefit of the dog species. These breeders perpetuate purebreds mainly, and while they might try to mitigate some of the problems associated with the breed, they are still culling the gene pool, with serious health implications for future generations.
Imagine the extreme scenario where we all got dogs from these 'responsible' breeders. There would only exist a carefully selected pool of purebreds and fashionable cross breeds. And as genetic testing increases, more would be culled from the breeding pool and from a select number of this smaller pool, the generations be bred. And from a smaller subset, would the next and so on. Do you see the issue here? We are reducing genetic diversity. This is ultimately to the detriment of the dog species.
(As an aside, bichon breeders are being urged to breed dogs with known health defects because a dog and their genes are more than the sum of their hips or eyes, and you don't want to lose the diversity in 'good' genes which might happen if you only focus on culling out the potential defects)
The maligned mutt, born from generations of random selection is the most genetically diverse and on average, the healthiest. But they would not exist if all dog reproduction was controlled by breeders.
Feesh, random mating is a or b in what I listed above. It may not seem random to you because in (b) owners are making a choice. But it is random from a genetic matching/ diversity perspective. Especially when done over time and over generations.