Why would a PCIe x16 slot be limited to PCIe x1 card?

Why would a PCIe x16 slot be limited to PCIe x1 card? pcie x1 slot function The PCI Express x16 slot is a versatile and powerful expansion slot that offers high-speed connectivity for various peripheral devices With pcie slot configuration gen1 gen2 gen3 PCI Express is a computer expansion card standard and is used most often for video cards PCIe is intended as a replacement to PCI

pcie slot configuration gen1 gen2 gen3 Your Motherboard provides 2-16X PCIE slots, which would be ideal for high-performance graphics card teaming via Crossfire in the case of this

pcie 50 slot The new Mac Pro with M2 Ultra combines our most powerful Apple silicon yet with PCIe expansion for the ultimate in workstation-class performance  PCIe x16 slots are generally intended for use with Graphics Cards PCIe 1x slots are generally for smaller add-in cards like Wifi Adapters, USB Adapters, or