If you create a build pipeline, and try to select as the first job a Jenkins Pipeline, it won't appear in the list, even if you write its name.
Also, if you have a Freestyle Job A, that calls a Jenkins Pipeline B, and you create a pipeline that starts with A, it won't show B.
In my case, I would like to start B manually, only after A runs. And most of times, it won't be immediately. So I would like to use Build Pipeline Plugin. Also, if some error occurs, i Would like to re-run B, so Build Pipeline is very useful in those cases.