I use Arch on everything at this point just because I have now learned its packaging system deeply enough to be able to write my own and do what I want with it.

That being said, there are Arch direct installers but ultimately Arch comes down to pacstrap. Thats like, the whole installer. Sure, it doesn't setup your bootloader or give you a root password, and without a locale a lot of stuff will break, but...

At this point I could easily write a shell script to do all the mechanical steps the way I always do, but in practice none of the steps are "hard" enough that there is a meaningful difference between reading a one liner in the install manual and doing something like ln -s your locale to /etc/locale.conf or picking it from a dropdown. And the stuff that is more complicated - partitioning, filesystems, bootloader, etc - there are way more choices in those than any installer currently presents. I get frustrated with a lot of distros over how hard it is to drop Grub for systemd-boot, for example.

If you don't want that absolutely use another distro or an Arch derivative, but there is a consistent trend line that the most widely tread path is the most well illuminated - if upstream Arch moved to an installer the manual process would decay over time to be much harder or impossible in the same way trying to manually install Ubuntu from a flash drive by copying files and manually writing configs would be a massive undertaking. Its a niche that exists because some of us wanted to know how it worked, wanted customization we couldn't get in installers, and just got used to it.

There is a reason unlike pretty much any other distro you can use any wifi management software that exists. Because nothing is assumed. Installers beget assumptions other distros make and untangling those for anyone trying to switch is often way harder than it is on Arch because it doesn't make those assumptions.