apple go to a lot of effort to make only their software work on their hardware, and vice versa, the days of the linux crowd caring enough to test it have long since passed.

whats the point in having a gui installed on a machine that by definition has no keyboard mouse or moniter (Aka a server)

they arent 3 "package managers". yum is a package manager, rpm is a package installer and dnf is a proposed replacement for yum. fyi https://en.m.wikipedia.org/wiki/Unix_philosophy

nearly all linux commands can be completed with around 4 key presses. e.g. aptTAB should give you apt-get