In my opinion, bitcoin open the gates for those who wants extra income. Like joining bounty campaign for this we can earn tokens.
Bitcoin is really a savior, it changed life of many Middle class people and as well as mine. There are many ways to make extra income in crypto space Examples are as follows: Investing, Trading, Bounties and Airdrops, Mining. You can also earn passive income by investing in DEFI but choose a good one which is creditable and paying rewards to its investors regularly since years.