Historically speaking, between average Android device and average Chromebook, latter is far easier to get mainline kernel + "normal" Linux distro running, e.g: 8 Chromebooks vs. only 1 Android device (and even that is a dev. board) in official Arch supported hardware list:
ALARM isn't official Arch, so this also isn't an "official Arch supported hardware list". Arch is currently still only x86_64 and everything else is at best unofficial if not just straight up unaffiliated.
(do note that this might change soon-ish™ considering [0], but I think they want to first get their automated build infrastructure ready)
So Arch on ARM is basically limited to an SoC with at most 8GB of RAM? It looks like we are still very far from a mainstream ARM motherboard with a socketed CPU, upgradable RAM and support for discrete GPUs. Until then, I see no reason to move away from x86.
> We're upstreaming core drivers for Snapdragon X2 Series — including the Hexagon NPU and Adreno GPU — to open the door to developers and partners.
Glad this isn't going to be some semi-proprietary thing like support for chromebooks. Hopefully it continues.