Computers used to come in proper full metal cases. Now they don't. Even when you try to find a metal case for a personal build most cases have giant holes in the side (case windows) acting as slot antennas. And plastic case laptop designs are even worse. Radiated emissions are much easier to achieve at useful intensities these days because of it. Sure, before the conductors going in and out radiated somewhat effectively (and still do). But now even core system components inside are just being let emit without any mitigation.