I was speaking more generally, not pandoc in particular. But even with packages in a manager, there have been times where different packages conflict on differ

I was speaking more generally, not pandoc in particular. But even with packages in a manager, there have been times where different packages conflict on different dependencies that when packaged up in a well written docker image (which not all are) would have obviated. As a developer I see this more with programming languages than other things, and this very thing is what led to language "package management systems" like rbenv, sdkman, asdf, and the like.