There are issues with both things. Population growth is bad for ecological reasons, and there have been fears of simply not being able to provide food and clean

There are issues with both things. Population growth is bad for ecological reasons, and there have been fears of simply not being able to provide food and clean water for the earth's population. Family sizes didn't really go down immediately once we figured out modern hygiene and medicine practices (many children died before modern times). We have a better handle on much of this, in part due better ways of turning ocean water into fresh drinking water. Of course, we are still suffering from pollution and waste issues that theoretically would go down as the population drops. On the other hand, we have uneven population growth, so some places are still exploding (Africa and some asian countries, for example). Birth control isn't readily available to all, neither is some modern hygiene and medicine. Population growth is still a problem for parts of the world. On the other hand, other populations are shrinking and people aren't having enough children to simply replace their parents. This creates all sorts of issues in itself. Partly because of manpower issues: Who is going to take care of the elderly? Will we have enough doctors, nurses, and farmers in these areas? And things of that nature. Some countries have addressed this through sex education, teaching both how to avoid pregnancy and how to get pregnant (and things that go along with that). Others have not. The best-bet solutions would be things like more service jobs and more automation where humans don't need to physically work, robots for care, and more open immigration policies so countries that are having overpopulation issues can freely relocate to countries with shrinking populations. IT wasn't that you were lied to, it is just a complicated situation that has changed over time.