This attack is pretty unrealistic. For one, China is extremely invested in Bitcoin, and if they were to seize equipement from miners it would be to drive up the

This attack is pretty unrealistic. For one, China is extremely invested in Bitcoin, and if they were to seize equipement from miners it would be to drive up the price, not try to kill it. For two, pricing hash power as USD ignores that they aren't the same. The US doesn't need to spend $9m per day (actually $45m per day, since this is from Jul 8, 2020 @ 9k, and BTC has since went way up) since they can't buy Bitcoin ASICs any better than anyone else can, and probably a lot worse since govt procurement is fucked. There's a limited amount of ASICs in the world, and no matter how much they subsidize the electricity cost it doesn't do anything until they have 51% hash power.