It is true that, nowadays, you can earn money by trading some bitcoin. However, by its nature, bitcoin is not something like that at all. Satoshi Nakamoto, its creator, has invented the system of block-chain as a way to make it possible a peer-to-peer payment system on the Internet without third-party organizations. Thus, for bitcoin to be a pioneer of a brand-new social model or to be something revolutionary, we should SEPARATELY consider bitcoin (and other virtual "currency") and currencies issued by nations.
Of course Bitcoin was created to revolutionize the traditional finance transaction system where people had to wait in long queue at the bank. Now with Bitcoin and the Blockchain technology, just a single touch at your own convenience will have all your transactions processed under good security, owner control, fast transaction and at low cost.
Also, you can earn some good profits by investing in Bitcoin especially setting a long term goal for that. Consider someone who bought BTC when the price was at $6K and now the price reaching almost $9K - that is a good profit margin and i don't think the story will end there, BTC is about taking another climb on the graph.