PCIe x4 and x8 cards can draw up to 25W from the motherboard's slot, while x1 cards are limited to 10W unless configured as a 'full-height' or 'high-power card' to pull the aforementioned 25W.
Ever since people figured out that the Raspberry Pi 4 has a PCIe bus, the race was on to be the first to connect a regular PCIe expansion card to a Raspberry ... have both PCIe x1 and USB on ...