Also, USB4 can optionally support PCIe tunneling, which is a fancy way of saying it supports plugging more advanced types of hardware in (like GPUs, high-speed network cards or NVMe SSDs) at speeds of up to 40Gbps.

And there is USB4 v2 (not kidding, that’s the name) which extends USB4 to up to 80Gbps, but there are no devices that support that yet.