You work offline on a "job definition" of some sort, submit it to the proprietary shared system, wait in a queue, then you receive a log file generated by a system you don't control. You can't run the proprietary system code locally on a workstation, and hence the inner loop is often tens of minutes long at best, hours or days at worst. There's no preview, no "what if" mode or "dry run". You work directly on production even if it's called "test" because there's only one system.
The real problem isn't YAML. It wouldn't matter if the pipelines were scripted in God's own programming language.
Software development on workstations instead of central timeshare mainframes became wildly popular because it allowed a dramatically faster inner loop, it allowed isolation from production environments, and it gave control back into the hands of the developers.
Current-generation CI/CD pipelines generally undo all of that.
Single-box Kubernetes reintroduces most of what made workstation-based development good, but it is still a very new system and has many teething issues.
PS: A related issue to yours is that there are great solutions for the solo dev doing click-ops for one app, there are great solutions for megacorops doing automation at scale for thousands of devs, but in the middle where you have a couple of enterprise devs managing a few dozen apps its just madness.