For me SRE/DevOps is just support for developers. It's possible that such person has more knowledge/experience in development and operations, but in general their focus is on infrastructure, automation and general troubleshooting.

They might know how to build/test/deliver/monitor some solution, they might know to some degree how to configure solution (but developers should support them with it and describe it well), how to script some operations, however they definitely won't write bugfix themselves.