I'm not the person you're replying to, but: I love dogs, I have a dog, and I think dog breeding is a net evil. I wish it would stop.

Edit: While it's admittedly over-the-top snarky, this video sums up my feelings nicely: https://www.youtube.com/watch?v=aCv10_WvGxo

There is an ethical version of breeding that would be good for society though (and I imagine this exists to some extent outside the mainstream mainstream). E.g. if a breeder decides "I want a hypoallergenic dog between 40 and 50 pounds with a calm demeanor who is otherwise maximally healthy" instead of worrying about the the nitpicky specifics of their appearance, that would be a benefit for society.

It's more the culture of dog breeding and showing than the concept that's harmful.

you just described proper poodle breeders: hypoallergenic, ~50lbs, bred for good demeanor (part of standard description, i believe) and do extensive genetic testing to exclude problematic lineages.

Personally I just worry that the result would be all dogs being pitbull mixes.

Why is that?

The traits that make a dog best for breeding in a more natural environment don't necessarily make them good for pets.

What does this even mean?

What does that have to do with dog breeding? Add to the fact, there's more than one way to be healthier and happier.

I'm not sure if this was the point he was trying to make but dog breeding is why dogs exist.