>Hashing is the easy part and because it is not reversible miners waste energy looping and trying different nonces so you get a hash with the required amount of zeros.
The above is massively computationally expensive, hence why it's not a fallacy.
The above is massively computationally expensive, hence why it's not a fallacy.
That is why you waste more energy (more expensive) now than years ago.
If the problem was adjusted where it wasn't using a double hash, and had some simple two-way function than it wouldn't be considered computationally expensive. That is irrespective of the length of the nonce. E.G if it was just a how much do I add to get a nonce of length x.
The complexity here is caused by the double hash.
The length of the nonce is just an even further scaling of an already difficult problem.