>>12537422
>so what happens when costs > reward?
difficulty is automatically adjusted when hash power is lower / blocks come in slower than they are supposed to
basically, miners with the lowest margins who go into the red will stop mining and the ones that are still profitable or at least aren't losing will get a bigger share of the cake.
end result is that the least efficient miners go out of business and the rest of the miners keep on mining
I'm not a big fan of POW in the long run, but the system is very well designed to prevent these kinds of issues automatically. With some blockchains like bitcoin, the difficulty adjustments can only happen after X amount of blocks where X is a pretty large amount. In such cases, if, say, someone were to increase the difficulty high by applying a lot of hash power, and then right after a difficulty adjustment, they sell a lot of coins and dump the price and keep the price low, while stopping mining on that blockchain completely, the remaining miners would be mining at a great loss until the next difficulty adjustment, and that difficulty adjustment could be many months away if the hashpower that was yanked away by the bad actor was a very large portion of total hashpower. If, lets say, that hashpower was 95% of total hashpower, that would mean blocks would be made 20 times slower until the next difficulty adjustment. In a blockchain like bitcoin where block time target is 10 minutes, that would mean each block (transaction confirmation) would be 200 minutes inbetween.