The in breeding to create “desired” features, such as flat faces, extreme smallness, disproportionately short legs. So many of these dogs have inherent problems such as breathing problems leading to infection, joint dysphasia etc. Look at the skull of a bulldog, it’s horrendous, no nasal...
I didn’t just mean the practical side like puppy farming, but also the fact of the horrendous in breeding , declining gene pool and all of the physical problems that brings for the poor dogs. I would never buy a dog that wasn’t basically wolf shaped for that reason.