alt Hacker NewsThey aren't normal computers in the same way x86 is. They usually need proprietary drivers in custom boot processes, forked kernels with patches, etc. I'm yet to see a single SBC I can just download the iso from the debian website and get going. You always need some custom build.
ARM boards need a custom kernel and bootloader. These aren't things managed by the distro. The userspace IS managed by the distro and IS standard. Using yocto to manage userspace maybe made sense 15 years ago, but it has long since become far more trouble than its worth. Debian supports most architectures out of the box, has good cross-building infrastructure, many thousands of ready-to-use packages, and is non-weird.