The goal is not to stop it, because that is not realistic and in reality, outside the high risk group of people with pre-existing issues (mostly older) not really necessary. In fact, for most of us, it is counter productive because it slows getting to the point where enough people have been exposed that it peters out.

The goal is to prevent a huge peak of infections that drive more people in those high risk categories to need medical help and overwhelm the medical system. It will take longer to get through it for most, but will potentially save lives of those by making treatment available.