You should ask this to your favourite distro packagers, not to the home assistant developers.
In any case, it is such a mess of dependencies due to load of optional packages, very active development, that continuously break dependencies on the package repo.
What advantage would bring have a most of the time obsolete distro specific repo? On a maintainer POV this is the typical use case for distro agnostic deployment, maybe flatpak, maybe docker.
Since HA depends on a lot of python packages, on external softwares and libraries it could not feasible to ensure that the versions packaged with the distribution will always be in line with those needed by HA