Having very frequent updates to bleeding edge software versions, often requiring manual intervention is not "stable". An arch upgrade may, without warning, replace your config files and update software to versions incompatible with the previous.
That's fine if you're continuously maintaining the system, maybe even fun. But it's not stable. Other distributions are perfectly capable of updating themselves without ever requiring human intervention.
> 2) the skill barrier to getting a full system is “basic literacy, to read the wiki”
As well as requiring you to be comfortable with the the linux command line as well as have plenty of time. My mom has basic literacy, she can't install ArchLinux.
ArchLinux is great but it's not a beginner-friendly operating system in the same way that Fedora/LinuxMint/OpenSUSE/Pop!_OS/Ubuntu/ElementOS are.