That's a good point, there is a vacuum for a good general purpose task automation tool that Jenkins has historically filled. The problem is that each of the ma

That's a good point, there is a vacuum for a good general purpose task automation tool that Jenkins has historically filled. The problem is that each of the magic functions you listed above are separate plugins. They're not part of Jenkins itself. Each plugin may (and often will) push breaking changes and vulnerabilities to your Jenkins instance, if they haven't been outright abandoned by their maintainers. Over time, your builds will steadily accumulate hacks to work around broken plugins, and your Jenkins instance rots.