Comment by pm215

This is a result of the market and its demands, not something specific to the architecture. In desktop and server, customers demand that they can buy a new machine and install a previously released stable OS on it. That means the vendors will implement the necessary standards and cross compatibility to make that happen. In the embedded market, customers don't demand that, and so vendors have no incentive to provide it. Instead what you get is that the specific combined hardware-and-software product works and is shipped with whatever expedient set of hacks gets it out of the door. Having a new cool hardware feature that works somehow or other is more important for sales than whether that driver is upstream or there's a way to describe it in ACPI.

Where Arm is in markets that do demand compatibility (i.e. server) the standards like UEFI and ACPI are there and work. Where it's in markets like embedded, you still see the embedded profusion of different random stuff. Where other architectures are in the embedded market, you also see a wide range of different not very compatible hardware: look at riscv for an example.