Dorsey's giving out some narrative of reducing pollution by making mining more efficient. This has to be him just saying things the media wants to hear, because that simply doesn't work. The pollution generated by bitcoin is not a factor of mining efficiency, its a factor of its price. When bitcoin reaches $100,000, its pollution will be roughly equivalent to the pollution created from making $100,000 worth of energy…
This is correct. But every 4 years, there is a halving. If the price of Bitcoin were to stay the same after each halving, then mining would be half as profitable so the amount of energy used by Bitcoin miners would drop by half. In 2012, the amount of new bitcoins issued every 10 minutes dropped from 50 bitcoins to 25. In 2016, it dropped from 25 to 12.5. In the most recent May 11, 2020 halving, the reward dropped fr…
You forgot the opportunity cost of the datacenter itself. It would be much more profitable to turn that into a colo or a VPS host with some new hardware.
Regardless, once the bitcoin reward goes low enough Bitcoin will probably become worthless. It's already not usable as a currency, and without the distributed ponzi system ofhanding out blocks to miners, what motive will anyone have to buy it?