At the end of the day crypto-currency is protected by the fact that it costs more to undo a transaction than the value of the transaction. Making an individual

At the end of the day crypto-currency is protected by the fact that it costs more to undo a transaction than the value of the transaction. Making an individual block easier just means that we have to wait for more blocks to be mined before we consider transactions to be safe. With you're idea there will be more blocks mined per hour, but the amount of electricity consumed per confirmed tx will remain constant.