“A 4090 series card will demand a whopping 450 W, which dwarfs the Ryzen 9 5900X peak power consumption of only 140 W.”
The GPU draws three times the CPU’s power and now ships with a support stick so it does not rip out of the slot. The motherboard layout still treats it as an add-in card. Nvidia keeps making cards bigger. Somebody has to redesign the case around the real computer.