In cities people take their pets to the vet when there is serious injury or illness or when an animal is at death's door. If their pet dies while being treated or operated on it is the norm, expected, that the vet will wave charges. And again, after a pet is put down it is deemed to be rude for the vet to charge a reasonable fee.
Rural regions operate in a different way. Veterinary surgeons are on duty 24 hours a day, 7 days a week. At lambing time they are rushed off their feet. Every farmer pays 3 months after service, so vets are in debt to the bank from the start. The days of paying with eggs are not gone either. Meat is often offered as payment.
Why do people train to be vets? They obviously love animals, like the technical side of the job, or have community spirit. They will not become wealthy nor have secure futures.