Yep, this is the answer. Tons of people are trying to cash in on dog breeding like beaniebabies. Frenchies, pitties (including XXL toadline monstrosities), random mixes (shitpoos, bernadoodles, cockadoodles, etc), etc. Breeding rights, stud fees, etc. are big business and essentially none of these "breeders" have any clue what they're doing.

In the vast majority of places in the US, there are no requirements or certifications needed to breed dogs. And now people will pay insane amounts of money for frenchies with rare coat colors, or pitbulls that are bred solely to be huge and squat with no concern about temperament or health; so irresponsible, backyard breeders who either ignore or are completely ignorant of proper breeding practice and refuse to get or can't afford proper genetic testing and medical care for their animals, are breeding for phenotypes like coat color or being insanely huge and squat and breeding in serious congenital defects and abnormalities.

Then either buyers are stuck with these shitty, genetically fucked up dogs they paid like $5k-10k for that now need thousands more in veterinary care to treat all the issues bred into the dog (not to mention parvo, parasites, heartworms, etc.). Or the breeder's little business collapses when they realize that they can't afford to continue operating their shitty puppymill due to the fact that dog breeding is expensive and their fucked up breeds can't give natural birth and so all need c-sections. But, it's usually the first one because there are no shortage of buyers willing to pay stupid amounts of money and trust the "breeders" because they assume they're experts.

So people often end up dumping the dogs when they realize they can't care for them medically or are aggressive or whatever else, while backyard breeders continue to pump out fucked up dogs for profit.