However, in our case (and probably many others), our devops team is responsible for creating and maintaining the tools and processes that allow the dev teams to manage their systems in production. At a larger organization, it doesn’t make since for each individual dev team to have to create and maintain their own deployment and management systems… that would end up with a lot of duplicated effort and a wide variety of systems that would need to be maintained. Devops creates the tools and procedures, and dev teams use them.
You might say this is just sysops, but I think the key difference is that the dev teams are the ones who are using the production management tools, not the sysops team. Devops is not the ones who are paged if a system has an issue, the dev team who owns it is paged. Devops is only paged if the tool that the dev team is using to handle the issue has issues itself.