pools get $13 million every day.
Security is expensive. POS doesn't work, And fakedollars (Stablecoins) that base their security on POS based based systems will hurt the most.
And if the first 3 pools want to make an attack?
https://miningpoolstats.stream/ethereumPOW mining also does not provide security for a coin if 3 large pools have a hashrate of more than 50% of the entire network. Mining is not as profitable right now, so reducing spending by $13 million per day could increase demand for the coin.