CPAN packages can be translated into perl packages automatically in many cases, or with little modifications. Same for python, ruby and node packages. See fpm[1] for example of one of such tools.
That's great, but distributions rightfully don't allow fpm generated packages. For all of these languages we've already got easy to use infrastructure, but maintaining a dozen or more packages just to get a single app in the repository is a huge commitment.
fpm is a bad example. Sure, it makes .deb or .rpm formatted things, but they are not proper packages by any means. Bundling up something pre-built from another packaging system is not what packaging is about. To do it right you need to build your own binaries from source code using only your own packages to provide the dependencies.
Of course, automatic translation of binary packages is bad thing which will produce wrong result in lot of cases, but automatic translation of source packages, with build instructions and meta-information, is time saver. For RPM, I will have a .spec file, which I then can edit further, or use tool options to fill fields with proper values. When .spec is ready, in most cases I will need to update version and changelog only to upgrade to newer version.
[1]: https://www.digitalocean.com/community/tutorials/how-to-use-...