PhD in mathematics, science communication jobs
A PhD is only "wasted" if you believe it is wasted. If you enjoyed your research, and it's helping you to engage in a long-term career you enjoy, why would it be wasted? 

However, there is a very clear need for people with solid scientific backgrounds who can clearly communicate complex mathematical and scientific ideas to the general public. People who can bridge the gap—for example, explaining concepts like "herd immunity" or "cryptocurrency"—in ways that the public can understand, are valuable in the scientific community, and we should be encouraging people to make that kind of outreach. It's not as popular as it should be in academia, but I believe that as more people engage in such careers, we will see room for growth. 

So if it's something you really want to do, go for it!