Apparently (from another comment on a thread about arm from a few weeks ago) consumer GPU bioses contain some x86 instructions that get run on the CPU, so getting full support for ARM isn’t as simple as swapping the cards over to a new motherboard. There are ways to hack around it (some people got AMD GPUs booting on a raspberry pi 5 using its PCIe lanes with a bunch of adapters) but it is pretty unreliable.