You can create bitcoins. Dollars (and all other national currencies) are issued by central authorities, but cryptocurrencies are issued by the blockchain members. Thus, investing your computational power and knowledge, you can earn bitcoin (and other cryptocurrencies) out of the air.
Bitcoin can be use in any transaction all over the world without tracking who use it while dollars are not, bitcoin has anonymity. You are the boss of yourself to earn bitcoin, you manage your own time, and can work even in free time to earn and get high income unlike to work with the dollar as salary.