See the start of this post talking about device tree models vs boot time hardware discovery.
There’s no reason an arm chip/device couldn’t support hardware discovery, but by and large they don’t for a variety of reasons that can mostly be boiled down to “they don’t want to”. There’s nothing about RISC-V that makes it intrinsically more suited to “PC style” hardware detection but the fact that it’s open hardware (instead of Apple and Qualcomm’s extremely locked down proprietary nonsense) means it’ll probably happen a lot sooner.