Going another step, I'd love to have a Thunderbolt to fiber adapter without having everything baked into a single cable. These products exist, but cost $5000 for each end
https://www.atto.com/products/thunderbolt-adapters/thunderli...
On a similar note I recently worked with an adapter that carries USB 2.0 over a cat5 cable. It doesn't even do that good of a job -- jitter is pretty high, which makes it useless for our use case of controlling a laser cutter live from a host computer -- but guess how much it costs? $736! https://www.blackbox.com/en-ca/store/product/detail/usb-20-e...