PCB layout is as much art and black magic as it is science. I'm not sure why you dismiss the complexity so easily, this definitely is not just a matter of applying Maxwell's equations.
Layout is a puzzle, especially with particularly high density layouts, but some of this is ameliorated by high layer count and fine trace/space boards becoming cheaper. Definitely not black magic. RF layout is black magic, let's not steal their thunder here.
High speed PCBs are RF. At high enough frequencies, traces become waveguides, and the result cannot be predicted analytically. Simulation is your only light in this mess.