I'll be sharing more about it later. But Top writer let's you know you have built a strong presence under that tag. And it's a breadcrumb from Medium saying "Hey dude, you may want to continue writing on this topic."
It happens when we have a lot of content under that topic, people have found us frequently under that topic, and we have trended on that topic as well.
If it is a smaller topic like self-growth, Medium doesn't notify you even though it is still impactful. Moreover top writer status is great for on-platform traffic if you use it correctly.
Yes, add it to your about section. It tells readers, I've built authority under this topic. I've got work to do on my about page concerning this I just put 4 x's but I haven't been specific.
I enjoy the questions, it let's me know additional research I can do for our community.
And I know you are top writer for that topic and tag because I'm right under you as of 3 days ago. 😁💛😎