You go into public health because you want people to be healthy. A goodly chunk of that consists of convincing people that they want to be healthy. They've been doing that for decades, on hundreds of diseases and conditions, long before COVID-19 was a twinkle in some bat's eye.
That's aggravating, frustrating work. It sucks, and you don't get a lot of big, obvious wins. But you do it because you think it matters.
There are a lot of things that they can do. It doesn't turn around millions of people overnight. But it does change minds -- they can see it in the surveys they take and in the numbers of people showing up in clinics.
Figuring out how to get the message out in a way that people accept and act on is real research and real science. Real research that saves lives -- even if they're not grateful about it, even in the face of an opposition intent on being obnoxious, even if the only way they can tell is in the ticking of a graph.
Because it's important to them that people not die.