Is the energy consumption inherent to 10Gbase-T? Or is it that 1Gbit nics have been around forever and optimised ad infinitum?

To be fair, the power consumption is also my biggest gripe with my WiFi 6 AP, they run extremely hot.

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.