You don’t run your own DNS, they are services hosted by someone else, just like Afraid. The difference, on top of the interface, is that they support modern record types, they have redundant servers all over the world, there’s a team working on them instead of just one guy, they have APIs that can let you manage your many domains easier, they have zone backup and restore etc.
I’ve used Afraid too, back when I was starting out and didn’t know any better, but once I’ve seen some of the other services out there I’ve never looked back. You’ll never know what extra features you could want if your current service doesn’t offer you any.