Bitcoin is the most efficient monetary network ever devised.All mining efforts, from whatever energy source, go directly into securing the network. All hashes matter. All hashes count. None are wasted.
by Adam Anderson on 14 May 2021
"Every Hash Is Sacred"
If a mass of new miners joins the network, the difficulty adjustment algorithm will automatically optimize the level of effort required for a block to be mined within two weeks at most (2016 blocks).
If miners leave the network, the same adjustment algorithm will ensure that blocks are produced every 10 minutes, like clockwork.
No other system of money or value transfer, accounting, supply generation, or discovery could be more efficient or secure.