Comment by CamperBob2

PCB routing is still a murderously-hard NP problem, AI or no AI. Not least because a fully-automated schematic-to-PCB flow has to be driven by component placement, which in turn is driven (or at least influenced heavily) by requirements further up the chain.

I'm sure it'll happen -- if you can defeat the world Go champion you can certainly route traces -- but so far it seems to be an exception to the bitter lesson, where proprietary hand-tuned algorithms are still on top. Given the lack of large quantities of PCB CAD files that can be appropriated for training, it might be one of those things that has to be self-learned by the AI, again reminiscent of how Alpha Zero worked.