DevOps is an analogue of Agile and Lean. Lean, which came from the Toyota Production System, doesn't just exist in one department and in one position. Saying that "DevOps is <x position> doing <x thing>" is like saying "Lean is a factory floor worker pulling an Andon cord when a product is defective". It massively understates all of the aspects of the method, and all the different roles involved, and how they get work done.
Nothing about these methods prescribes that you have to use X technology, or that there is just one position that does work in one way. They prescribe a method, and you choose how you implement that method, and lots of different kinds of people in an organization are needed to make it all work.
I started a Wiki recently to try to give some more in-depth understanding of DevOps (https://devops.yoga/overview.html). It's still pretty bare-bones, but I think you can quickly get the idea that DevOps isn't one particular thing, or one particular team, or one set of technologies.