The betterment of the healthcare area

Until about 200 years ago, the populations of humans on this planet was a stable, and then people used to have 10 to 12 kids, and marry 3 or 4 times in their lives. And about 5000 years ago, no one used to marry. Thats how wild it was. But still there was no population explosion. Why was that? The birth rate was equal to the death rate. But things have changed now, parents no longer have to product 15 to 20 kids to carry on their genes. Just 1 is more than enough. Thats the magic of health care. People can choose to stay healthy now, drink only purified water, eat only food of the highest quality, and use ultra perfect sanitary systems. Lots of people are getting into jobs in healthcare with their medical resume, and apart from making a good deal of money, they are doing a real service.