I wish they would just have direct PCIe lanes. For most of the cards doing those speeds USB is just unnecessary overhead

They sort of do in the 16 with the dual M.2 adapter:

https://frame.work/pl/en/products/dual-m-2-adapter

People have been making custom OCuLink adapters and recently Framework developed its own:

https://frame.work/pl/en/products/framework-oculink-dev-kit