It depends on whether or not they consume more as a result really - think about it, is the number of joules to transmit down a wire different at different speeds? I'd guess probably not
It wasn't that serious... and still need to process 10-100 gigabytes files for work sometimes, and am doing fine with my 50 Mbits... I just cannot imagine one person really.making good constant use of 2.5 Gbit, and in the rare times needed not just invest a little time, so I think it is money wasted in this case. Admitted, my imagination may be too limited and it is a valid tradeoff of time vs money.
But yes, nitpicking, but on the same tech it should be insignificantly more joules also, different techs or hw much more significant though.