There's an interesting quirk of history that lets you run linux on an arbitrary PC.
In the beginning, there was the IBM PC. And then lots of folks copied it to make systems that worked samishly enough that you had a standard platform. And as time went on, there was an actual standard. Well, many standards, which are standard enough that they mostly are cross compatible.
Within the same architecture OSes are portable, and within the same OSes, applications are portable. That's really cool, and why I can still install windows 10 on a 10 year old core 2. I however, can't take a rom meant for my brother's galaxy s7 and install it on my oneplus 3 and just 'add a few drivers', despite having the same processor
Arm does not. In fact, there's multiple vaguely incompatible platforms -, and android tends to be built per device. There's no standard bootloader even - companies build their own, though you can replace those. While there's a standard platform for ARM - its for servers.
So essentially you'd need to build the entire system stack from the ground up, for the quirks of your system.