It is not a OS over an OS just some packages that are preinstalled
EndeavourOS has its own packages ( https://github.com/endeavouros-team/PKGBUILDS ), but they are mostly driver stuff and some presets for the different desktop environments. Rest is all from arch, arch extra, arch extra multilib(32bit) and AUR.
And yea, you understand it right, if you don’t want help managing arch, it is not for you.
I prefer the trippy tribe 🥴