The problem isn't support for the ARM architecture in general, it's the support for this particular board.
Other boards like the Raspberry Pi and many boards based on Rockchip SoCs have most of the necessary support mainlined, so the experience is quite painless. Many are starting to get support for UEFI as well.
For example I have an Orange Pi 5 Plus running the totally generic aarch64 image of Home Assistant OS [0]. Zero customization was needed, it just works with mainline everything.
There's even UEFI [1].
Granted this isn't the case for all boards but Rockchip at least seems to have great upstream support.
[0]: https://github.com/home-assistant/operating-system/releases