As the value of the coins fail (naturally), the negative part of the game is the cost it takes to mine them overtakes it’s value, the losses when it broaches that line will be the collective cost that the holders of bitcoin will have paid the miners The real tragedy will be that that loss will be irretrievable, it will have literally gone up in smoke, a social loss.
Looking at CryptoSlate.com the PoW consensus algorithm accounts for 41% of the market, $351.33B. While the Proof of Stake consensus algorithm – the one that doesn’t do the energy intensive mining – accounts for 28.28% of the market and $240.95B, there’s also Delegated Proof of Stake with another 1.85% of the market.
The market cap of Bitcoin alone ($323.30B) is greater than the marketcap of PoS as a whole (which now includes Ethereum), but Bitcoin market cap is 92% of the PoS market, so it’s only bitcoin keeping Proof of Work as the dominant consensus algorithm, and that’s only for historical reasons, not because it’s better.
The cost of mining won’t be the death of crypto, because a) since when has the cost of anything stopped people, and b) because it’s not the whole story.