Anyway, the design of Bitcoin makes it so that any reduction in the total cost of mining only increases the difficulty until the total cost approaches the value of the block reward.
PoS costs nothing. so PoS coins have a zero cost acquisition of creation and just rely on the cost acquisition of people buying it to support a bottomline value.
if gold cost $1 to mine, the price of gold would tank because miners would sell it at instant profit to value at $1 and speculate (hype, FOMO) above that in bubble prices/waves if ups and downs above that. in the $2 area
in bitcoin mining. SMART miners plan a year in advance. they get their FIAT from private investors to cover the bills. and in exchange the private investors get BTC at a certain rate. thus not impact the market directly
some smart pools when bitcoins price is below mining cost. they actually buy the coin on the market and hand that to the private investor. thus keeping the price up (afterall why waste electric to get something more expensive)
there are a couple silly mining farms that actually pushed the boat and foolishly went short term sighted turned off too many rigs during alst december. sold load of coins to buy more rigs an then turned loads of rigs on after december. to then realise they had to turn loads off when the price couldnt sustaiin them
thus having to sell the rigs at second hand discount
https://data.bitcoinity.org/bitcoin/hashrate/2y?mining_pool=BTCC+Pool&t=aBTCC was victim to this.. and now sits at the dizzying low of 0.5% network hashrate
where as pools like antpool. just played the progressing increase every few weeks and just paying off their investors. which is why their hashrate has shown a more smooth progressive climb not really reacting to price swings of the market.
https://data.bitcoinity.org/bitcoin/hashrate/2y?mining_pool=AntPool&t=aanyway
smart mining pools locate themselves near energy grids where the power company produces more electric than the population demands. and this electricity excess cant be recouped/stored, resent out later... and so they would just lose it without making any money.. so smart pools buy some of that excess. which pools love as they get a discount. and power companies love because they get money for nothing.