Responsible people are perfectly capable of preventing unwanted puppies. They don’t neuter over much of the rest of the world. And for every health benefit, there is a health detriment.
Irresponsible people are the problem and neutering by responsible people won’t cure that issue, and the irresponsible people still won’t do the responsible thing and neuter their dogs.
Betsy did the right thing and neutered her dog with an undescended testicle and I did the right thing by neutering my dog with food allergies, but that will not affect the over population problem, because neither dog is running around loose to go breeding puppies anyways.
