Efficient how? Efficiency is a meaningless term without a metric attached. A train is efficient in terms of CO2 used per kg transported, it's not efficient in terms of time to transport.

> Attacking them for size

I didn't attack them for size, I attacked them for energy consumption. And that has multiple knock on effects. From climate change (since a lot of these data centers are being powered by natural gas), to local air pollution, to increased local and regional energy prices. If you are consuming 9GW of natural gas that's 9GW worth of physical gas that's been consumed. Increased demand == higher prices for anything that uses natural gas, heating and power generation come to mind.

I don't care so much if a data center is huge, what I care about is the resources it consumes to operate. Similar to how I don't care how time efficient a private jet is for the wealthy to fly on. I care more about of CO2 inefficient private jets are.