A GUI that lists all the available options is much more user-friendly than a YAML configuration file where you have to guess them or pore over documentation before starting, but even Jenkinsfile syntax looks better than YAML, and Groovy is a real (edit: realer) language that, in theory, can have things like syntax highlighting and auto-completion.
I knew someone would try to say groovy was a real language.
I miss the good old days with bash scripts and cron.
Why must so many diverging environments and tools mingle in our mental space.
As for cron, that's also supported out of the box.
At that point Jenkins is mostly acting as a nice frontend to all those cronjobs and shell scripts, but at least it keeps records of all the logs etc.