Obviously we don't have AGI so we can't compare many tasks. But on tasks where AI does perform at comparable levels (certain subsets of writing, greenfield coding and art) it performs fairly well. They use more power but are also much faster, and that about cancels out. There are plenty of studies that try to put numbers on the exact tradeoff, usually focused more on CO2. Plenty that find AI better by some absurd degree (800 times more efficient at 3d modelling, 130 to 1500 times more efficient at writing, or 300 to 3000 times more efficient at illustrating [1]). The one I'd trust the most is [2] where GPT4 was 5-19 times less CO2 efficient than humans at solving coding challenges

1: https://www.nature.com/articles/s41598-024-54271-x?fromPaywa...

2: https://www.nature.com/articles/s41598-025-24658-5