What can you do with Bitcoins but can't do with Dollars?
Well, firstly, earn a ridiculous value increase. Secondly, I can sell bitcoin for a ridiculous fee. Thirdly, I can market physical
BTC coins as if they were unicorns, and consequently earn a profit on them as if they were unicorns. Etc...
Bitcoin price sometimes increase. It's value varies fron time to time and it's currency can't be use and still has to be changed into state money unlike dollar whose value is steady and is physically present.