I don’t disagree in anything you say here, with the exception of misunderstanding. Manjaro, Artix, Devuan, Fedora are linux systems. When a newcomer in linux looks at the market shelf they notice that they (out of the box installers) “support” certain architectures and certain DEs. Not even debian doesn’t have a complete list. There are others that only come in one DE, but except for networking, servers, sysadmin tools (grml, rescatux, etc.) they most likely do come with a DE.
In Manjaro, if one was a fan of LXDE a look at the forum showed that there is a good base for it.
I don’t want to get into what M-OpenRC in terms of functionality had different from M-official edition. It is not the place anymore. But there were several issues with functionality difference, despite of DE, but were evident to the DE user.
It is not a place to discuss gnome DE and its relation to the core system. I believe it would have been possible but it would be like a dog spinning around trying to catch its tail, running gnome on a systemd-free system. And there are gnome packages and libraries that many others are using. Soon you may lose mozilla to such a maze.
So, in fundamentals we agree, but in details there is a front beyond the core system, and that is to make what most people (users) use work in such a system.
Then there is the issue of artix, it comes with LXQT available on the installer, as ManjaroOrc came with xfce. Were people here because manjaro core system was better than arch? One look at / directory structure and you can tell it is different, but that is not why the overwhelming majority was here and not in arch.