Hey, I use it at work. It's really just a fairly stable way of documenting APIs. Sure you can try do fancy generation of it from one side, and generate code on the other, but treat it just as a standard way of talking about requests and responses and you'll see the benefits.

If you do want a good benefit, here's a testing engine that'll run through an OpenAPI file and confirm the server's adhering to it correctly: https://dredd.org/en/latest/