I agree to you that bitcoin is decentralized and bitcoin can be used as the mode of payment in some business online and can be used to send funds wherever you are or whenever you want. Bitcoin is a decentralized truth ledger and a digital currency that involves in blockchain and cryptocurrency. You can earn bitcoins in many ways that can sure you'll be a millionaire someday and the ways on how you can earn bitcoins are Mining, Trading, Gambling, Investing on bitcoin related businesses, Joining in signature campaigns here in the forum.