Arch is aimed at people who know their shit so they can build their own distro based on how they imagine their distro to be. It is not a good distro for beginners and non power users, no matter how often you try to make your own repository, and how many GUI installers you make for it. There's a good reason why there is no GUI installer in arch (aside from being able to load it into ram). That being that to use Arch, you need to have a basic understanding of the terminal. It is in no way hard to boot arch and type in archinstall. However, if you don't even know how to do that, your experience in whatever distro, no matter how arch based it is or not, will only last until you have a dependency error or some utter and total Arch bullshit® happens on your system and you have to run to the forums because you don't understand how a wiki works.
You want a bleeding edge distro? Use goddamn Opensuse Tumbleweed for all I care, it is on par with arch, and it has none of the arch stuff.
You have this one package that is only available on arch repos? Use goddamn flatpak and stop crying about flatpak being bloated, you probably don't even know what bloat means if you can't set up arch. And no, it dosent run worse. Those 0,0001 seconds don't matter.
You really want arch so you can be cool? Read the goddamn 50 page install guide and set it up, then we'll talk about those arch forks.
(Also, most arch forks that don't use arch repos break the aur, so you don't even have the one thing you want from arch)
I mean, you are right, and way more people should be using openSUSE :P
I will say Arch-derived distros are a good experience if you want to learn how the terminal and other systems work. They're engineered to be configurable; the documentation is great. But if you just want to use your computer without opening too many hoods, it's fundamentally not an optimal system.
Another thing is that many people just want their new laptop to work, and for it to game on linux. Sometimes it does not just work. If you start pulling in fixes and packages that are not supported on your distro, you can screw up any distro very quickly (and this includes the AUR, unofficial Fedora repos and such). If the community packages these, stages them, tests them against all official packages, and they work out-of-the-box... that's one less hazard.