and we will have a really low power consumption for people around the world.
Why should consumption be lower? People will just add more asics or FPGA because right now electricity is the limiting factor. So there's no way global consumption will reduce.
Dude, there is not a unlimited storage or production of FPGA's. There are only a few FPGA's currently on the market and look how much GPU's are floating around the globe. Im not sure about the amount of FPGA's, but Im sure that if we have just for example 10 Million GPU's there will be only like 50k FPGA's.
So just calculate that again, if the FPGA's only take 150W and one GPU 100-300W depend on the model!