> Isn't there a mathematical puzzle which cannot be optimizer by GPU usage so that desktop and phones are on par?
If you can answer that question, you can create a blockchain Proof-of-Work algorithm that won’t use half the world’s electricity.
If you can answer that question, you can create a blockchain Proof-of-Work algorithm that won’t use half the world’s electricity.
The global annual consumption for 2017 was 21,372 TWh. [2]
While Bitcoin's energy consumption is notable, it accounts for nowhere close to half of the world's electricity usage, but rather about 0.3% of it.
https://hackernoon.com/the-blockchain-scalability-problem-th...
But in the context of "what if the the whole world uses bitcoin", the vast majority of transactions will not be onchain. But instead will be transacted via other more efficient layers (sidechains - like Liquid, or level 2 - like lightning).