USB4 v2.0 will be a technically superior solution to PCIe 4.0 over OCuLink 4i once it’s out. It’s a sturdier cable, capable of enough wattage to power a lower-power GPU, and can carry 7.65~8.32 GiB/s or 65.71~71.47 Gb/s (depending on the PCIe TLP payload size supported by the device) after subtracting line encoding, FEC, and packet overhead. If ASMedia’s USB v2.0 implementation supports asymmetric operation, unidirectional bandwidth could hit 11.48~12.47 GiB/s or 98.61~107.12 Gb/s. That’s the equivalent of 6~7 PCIe 4.0 lanes.
The PCI-SIG are developing external connectors for at least 3 generations of PCIe revisions starting from 6.0, but who knows when they’ll be available.