FWIW, a 10m 5gbps optical USB cable is $70 in the US including 1-day shipping. Dunno why anyone would pay hundreds of pounds even with the euro/pound tax.

Also compare to data center hardware. A 10m 10gbps active optical cable is only $31 retail: https://www.fs.com/products/30895.html

Normally you'd buy optics and fiber (which is cheaper than copper ethernet cables of the same length) separately for data center use and in larger volume, but my point is that there's no expensive tech involved in these cables.