That would be true, but eGPU docks often include a few USB ports and possibly Ethernet to make them advertise as docks. To… mixed results.
I think I found an obscure one with dual cables specifically to give the GPU maximum bandwidth. It’s just not quite a mainstream market, so attracts limited investment. IMO.
It is a product that suits the Framework particularly well though, so it keeps coming up here. Really cool seeing some of what’s going on, too.