Earlier quoted context omitted.
In a way, bitcoin itself is not really a currency, or money, it's more like an idea for exchanging messages. Bitcoin is really a decentralized messaging system which relies on cryptography and proof-of-work to maintain integrity. Should exchanging messages in the form of "I owe you x amount" over a p2p network be regulated or be made illegal? However, The fact that it's used as a form of currency is just an interpret…
They are also disastrous for the planet - bitcoin's carbon footprint is growing, trading our planet for ... imaginary points. This has got to stop.
As the mining reward rapidly dwindles relative to the cost of electricity, there is a huge incentive to reduce the electricity consumption while maintaining the security of the network. At what point does this reach an equilibrium depends largely on the market value of bitcoin. So it should be a somewhat fixed cost in proportion to the adoption of bitcoin, just like the fixed costs of any currency (e.g. minting coins, mining gold, etc.).