What does a maintainer realistically do?
He builds the software, so you expect that the package builder automatically installs the development dependencies and runs the build software inside a chroot.
In case the software requires modifications, there needs to be a way to deliver patch files or additional files that aren't part of the original software or at least a standard location to store the distro specific fork that everyone agrees on.
Once the software is built, the maintainer creates a directory structure that conforms to the distributions's conventions, adds things like systemd unit files or desktop shortcuts and other distro specific changes that exist outside the software.
I would encourage everyone to at least give Alpine or Arch Linux packaging a try. It really is quite easy. Almost as easy as writing a docker file.