Exactly. Packing components isn't the problem. Routing traces isn't the problem. Both of those can be accomplished with fairly straightforward algorithms. We've had auto-placing and auto-routing for decades, and they serve their purposes well enough.

The hard part is that 98% of laying out a PCB has nothing to do with laying out a PCB. The hard part is analyzing and predicting how every individual trace or component interacts with literally all other traces and components at once. You have to track and model current paths, ground and power plane inductance. You have to just know what parts of the circuit are critical and which traces to keep away from others. Almost all of the work involved in producing a PCB is in designing and understanding the circuit and the physical implications of each and every section, wire, and component.

Routing a PCB is easy. Engineering a correct PCB is not, and there's a lot more involved than drawing traces between pins.

I find it actually pretty confusing that people are still trying to automate the naive approach to PCB design. If your circuit is simple enough to not care about the finer details, traditional algorithms are all you need. For anything more complex, placement and routing just aren't the primary problem, and you can't solve the real underlying challenges by solving placement and routing.

I don't think these problems are inherently un-computable, but they are very hard problems that take humans many years of training and experience to work through. I think they are likely beyond our reach for the moment.