I have been at this for 25+ years and I remember the days of silos. I remember developers passing off code to QA and it coming back days later with bugs. I also remember a lot of 'not my problem' coming back from developers. Sometimes it wasn't their problem; often it was.
Either way, the person with intimate knowledge of how the code works should be the first person that looks at the problem. In SaaS, that is production and should be the developers (within reason).
As Ops, my goal is to make that as easy for possible for developers. That means automating everything I can so that the right tools are in place for deploying, monitoring and alerting are there. It means that I have to automate spinning up and destroying infrastructure as quick and easy as possible so that we can meet your needs and also keep costs down.
I have also seen companies fail at becoming 'devops' in the most terrible way. They took developers and made them own everything from code to deployment to VMs. The developers had so many pieces to understand that the only guarantee was failure. That was a terrible startup to work at.