Modern transceivers can do 10G on absolutely garbage twisted pair. My house was wired with absolutely dire cat5 cabling. Zero shielding and barely any copper in the pairs. I thought I'd barely be able to do 1G on them, but modern transceivers (amazon) easily do 10G over like 30M of that sort of cables.

In fact I had more trouble getting quality fiber working for that sort of distance than El Cheapo cat5. They do heat up a bit, but they work wonder.

Zero shielding may actually help. Shielding acts as an antenna when not properly grounded and continuous, which is more common than not.