It's inherently worse than anything fibre, or even DAC cables (which are kinda cheating.) It needs a shitton of analog "magic" to work with the bandwidth limitations of copper cabling.
10Gbase-T, to try to get to 100m, throws FEC on it and converts the signal to 4x PAM-16/THP at 800 Mbd, and then uses 4 copper pairs *bidirectionally*. That's the analog magic.
Yes, that signal processing is massively more expensive. A 10Gbase-T PHY is a sophisticated DSP. Not sure if the power needs are exponential, given we only have a few data points, but it's in the ballpark.
(1000base-T PHYs are already DSPs, but nowhere near as sophisticated)