I get your sentiment but I don't think this works in theory.
Firstly, we tried for a few years to rehome a dog from any animal shelter around us, we were always super close and told we were fantastic candidates (young couple, good income, garden, flexible hours, provision to ensure dog would never be left alone, prior experience of training dogs and good knowledge of the breeds we were interested in and no children at that time plus I volunteer in an animal shelter with the dogs. We were passed over every single time and ended up going through a reputable breeder because we knew we wanted to have a family eventually and needed time to train and socialise a dog well in advance of that. Obviously the shelters were going with the best candidate for the dog in question which meant people who were retired, living in the country with other dogs of the same breed which is absolutely fair enough. But you can't suggest that anyone can walk into a shelter and rehome a dog if they meet the criteria. It doesn't work like that.
Next issue- most people can afford a healthy dog. Few people can afford a seriously unhealthy one and the majority of dogs coming through rehoming services now are the result of severe inbreeding and puppy farming. Its much harder to get a healthy dog from a shelter now and it's important people are realistic about their finances. Most insurers won't cover existing conditions so it's very different than having a healthy pup and them becoming ill later on.
Also, some breeds have been bred to certain unhealthy standards like inverted faces, underbites, teacup size etc. Ethical breeders are now needed to undo that damage and create more health in the breed saving the dogs from needing operations to correct the issues that come with breed standards. You can't rely on dogs from shelters for this because so many of them have poor health that you wouldn't want continued through their lineage at all.
I think the problem is that proper ethical breeding is lumped in with puppy farming and backyard breeding to make a quick buck with no prior thought or safeguarding. But it's up to the prospective buyer really to be more discerning. I know I can stand over my dogs lineage and the health of that lineage and the care that he got while with his litter, if people didn't buy from puppy farms and unethical breeders then there would be no demand and they wouldn't continue doing it.
In terms of anti social behaviour from dogs etc I think the best way to deal with that is having training / socialisation classes mandatory for licensing. I know plenty of people who bought beautiful dogs from breeders but haven't trained them properly. Thats not the breeders fault it's the owners.