> There a large number of developers around now who've never done traditional (RPM, DEB, SysV) packaging and don't understand it.

I'm one of these developers (at least as far as my day job is concerned) and the only methods of delivery in a professional context that i've seen have been:

  - delivering .jar or .war application files (Java), mostly through FTP or even e-mail
  - delivering other files, like documentation etc., mostly through FTP or even e-mail
  - using containers and pushing images to registries (mostly due to my initiative)

This is across ~5 years of software development and while looking at projects from multiple companies in my country - not once have i seen a DEB or RPM package repository be used. To me, it seems like previously people opted for the simplest solution in their eyes, which was just shuffling a bunch of files around through FTP, i guess since that doesn't lock you down to using a particular distro or even OS.

However, streamlining that process on our end and eventually migrating over to containers, to where both the CI and CD are automated (or at least based on a manually invoked pipeline, when we're sure about making a release) seemed to be a no-brainer. Suddenly delivering software isn't something that takes an hour - even if needless cruft (making Jira issues manually etc.) is still there, any automation and getting rid of the human factor makes things safer and easier.

That said, it surprises me that previously no one bothered to set up their own DEB or RPM repositories, since then the clients could use the package management solutions that they're already familiar with. Any idea what are some of the reasons for it? Why doesn't everyone just make it so that their software can be installed and updated through apt/yum/...?