Miners cannot use expensive electricity and therefore cannot expand unless they find really really cheap electricity rates.....which are apparently unavailable? lol.
US-based miners use the absolute cheapest they can find, as doing otherwise would make them globally non-competitive, as e.g. miners in Paraguay have access to lots of excess hydroelectricity, or miners in Kazakhstan have access to cheap coal. Since hashing units are more or less the same, it all boils down to electricity costs.
Miners even go as far as using methane from animal waste to find absolute cheapest fuel: https://financefeeds.com/unusual-way-power-crypto-mining-ani...
Burning animal waste methane is actually carbon negative, wonder if anyone on this board will finally acknowledge that mining can be good for the Earth, if done properly.