I am a Linux user, but I don’t really know how most things work, even after years of casual use on my Main, I just started getting into Devuan and wondered then, what exacly does systemd do that most distros have it? What even is init freedom? And why should I care?
NetworkManager (network interface/connection management)
Pretty sure you mean systemd-networkd here. I find systemd-networkd to be very nice for headless systems, but NetworkManager seems to be a better fit for desktops because of the integrations it has available with KDE/Gnome/system tray