Why does 10 Gbps Ethernet require fibre optics while my 40 Gbps Thunderbolt cable is copper?

Hi! Networking noob here with a question:

To reduce the risk of getting strangled by the mess of cables on my desk I gifted myself a Thunderbolt 4 docking station which handles bandwidths of up to 40 Gbps. Rerouting all the cables made me remember a student job I had at a data center a couple of years ago, where I installed the hardware for a 10 Gbps network which included plugging in a lot of those large cables.

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Now here's my simple question. How come my regular copper Thunderbolt cable does the job while the data center had to use fibre optics? It this only due to the fact that, in general, the required cable lengths are much larger for ethernet?

Thanks 🙂