Before you assume that the c-section is the culprit when a bitch and her puppies do not do well afterwards, ask yourself these questions:
When was the cesarean performed? Breeders often have an emotional (or financial) aversion to c-sections and thus wait until their bitch is long overdue, and/or weak and exhausted before finally caving in and taking her to the vet. Poor milk production can hardly be blamed on the c-section in that case.
How long were the puppies stuck? Were they hypoxic (deprived of oxygen)? Listless post-C section puppies are probably more often due to the stress of being stuck for too long, rather than the ill effects of anesthesia.
Was the veterinarian a skilled surgeon? Don’t just assume your regular vet is going to be able to do a good c-section for you - ask a lot of questions. You need a vet who actually regularly performs c-sections, who has a trained staff to assist.
What kind of anesthesia is the vet using? Years ago, anesthesia left mothers and puppies groggy, but newer anesthesia drugs are very different, offering almost an immediate recovery for both the bitch and her puppies. Don’t assume your vet is using the latest and greatest anesthesia drugs - ask questions.
I’m not going to “take a stand” on doing c-sections, but I will take a stand on being prepared to, should it be necessary with these three things, at minimum,