Connecting devices with PCIe to RPi5 : rraspberry_pi

Geekworm KVM-A8 PCIe Version for Raspberry Pi 4 Model B KVM raspberry pi 4 pcie slot Honest question, why is the PCIe slot available in the Pi4 CMIO board combination not sufficient for a dual gigabit ethernet NIC? A PCIe raspberry pi pcie slot Geekworm KVM-A8 PCIe Version for Raspberry Pi 4 Model B KVM Over IP : : Computers & Accessories

raspberry pi 4 pcie slot Storage Card: microSD slot The Raspberry Pi Compute Module 4 has the PCIe x1 bus