Hopefully in this world, someone figures out how to deliver the performance equivalent of a B300 GPU for about 1/100th the power of a current B300 (which can be up to 1400 watts), or the world will bake.
Analog AI/approximate computing? There's research into it, worth looking at if you're interested.
The idea is you tolerate some loss/degradation (which neural networks do) but gain orders of magnitude power efficiency.
8 biillion * 1400 watts = 11.2 terawatts
current global average electricity production = approximately 3.6 terawatts
But then again these systems do not use 1400 watts all the time. We would probably have much more then 11.2 terawatts demand if all humans turn on all their electrical consumers at the same time.