In the olden days of 10 years ago, most operations teams worked around the clock to service the application. Like every day there would be someone on my team doing something after hours usually multiple. Tools like Kubernettes, Cloud (AWS, GCP, Azure) have added significant complexity but moved operations to more of a 9 to 5 gig. Less and less do I see after hours deployments, weekend migrations, etc. Even alert fatigue goes way down because things are self healing. This is on top of being able to move faster and safer, scale instantly, and everything else.
Operations side used to be a lot of generalists admin types and DBA's. With today's environment, you need a lot more experts. AWS alone has 1 trillion services and 2.4 billion of those are just different ways to deploy containers. So you see a lot more back end roles because it's no longer automate spinning up a couple servers, install some software, deploy, monitor and update. It's a myriad of complex services working together in an ephemeral environment that no one person understands anymore.